xref: /sqlite-3.40.0/src/pragma.c (revision f2fcd075)
1 /*
2 ** 2003 April 6
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This file contains code used to implement the PRAGMA command.
13 */
14 #include "sqliteInt.h"
15 
16 /* Ignore this whole file if pragmas are disabled
17 */
18 #if !defined(SQLITE_OMIT_PRAGMA)
19 
20 /*
21 ** Interpret the given string as a safety level.  Return 0 for OFF,
22 ** 1 for ON or NORMAL and 2 for FULL.  Return 1 for an empty or
23 ** unrecognized string argument.
24 **
25 ** Note that the values returned are one less that the values that
26 ** should be passed into sqlite3BtreeSetSafetyLevel().  The is done
27 ** to support legacy SQL code.  The safety level used to be boolean
28 ** and older scripts may have used numbers 0 for OFF and 1 for ON.
29 */
30 static u8 getSafetyLevel(const char *z){
31                              /* 123456789 123456789 */
32   static const char zText[] = "onoffalseyestruefull";
33   static const u8 iOffset[] = {0, 1, 2, 4, 9, 12, 16};
34   static const u8 iLength[] = {2, 2, 3, 5, 3, 4, 4};
35   static const u8 iValue[] =  {1, 0, 0, 0, 1, 1, 2};
36   int i, n;
37   if( sqlite3Isdigit(*z) ){
38     return (u8)atoi(z);
39   }
40   n = sqlite3Strlen30(z);
41   for(i=0; i<ArraySize(iLength); i++){
42     if( iLength[i]==n && sqlite3StrNICmp(&zText[iOffset[i]],z,n)==0 ){
43       return iValue[i];
44     }
45   }
46   return 1;
47 }
48 
49 /*
50 ** Interpret the given string as a boolean value.
51 */
52 static u8 getBoolean(const char *z){
53   return getSafetyLevel(z)&1;
54 }
55 
56 /*
57 ** Interpret the given string as a locking mode value.
58 */
59 static int getLockingMode(const char *z){
60   if( z ){
61     if( 0==sqlite3StrICmp(z, "exclusive") ) return PAGER_LOCKINGMODE_EXCLUSIVE;
62     if( 0==sqlite3StrICmp(z, "normal") ) return PAGER_LOCKINGMODE_NORMAL;
63   }
64   return PAGER_LOCKINGMODE_QUERY;
65 }
66 
67 #ifndef SQLITE_OMIT_AUTOVACUUM
68 /*
69 ** Interpret the given string as an auto-vacuum mode value.
70 **
71 ** The following strings, "none", "full" and "incremental" are
72 ** acceptable, as are their numeric equivalents: 0, 1 and 2 respectively.
73 */
74 static int getAutoVacuum(const char *z){
75   int i;
76   if( 0==sqlite3StrICmp(z, "none") ) return BTREE_AUTOVACUUM_NONE;
77   if( 0==sqlite3StrICmp(z, "full") ) return BTREE_AUTOVACUUM_FULL;
78   if( 0==sqlite3StrICmp(z, "incremental") ) return BTREE_AUTOVACUUM_INCR;
79   i = atoi(z);
80   return (u8)((i>=0&&i<=2)?i:0);
81 }
82 #endif /* ifndef SQLITE_OMIT_AUTOVACUUM */
83 
84 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
85 /*
86 ** Interpret the given string as a temp db location. Return 1 for file
87 ** backed temporary databases, 2 for the Red-Black tree in memory database
88 ** and 0 to use the compile-time default.
89 */
90 static int getTempStore(const char *z){
91   if( z[0]>='0' && z[0]<='2' ){
92     return z[0] - '0';
93   }else if( sqlite3StrICmp(z, "file")==0 ){
94     return 1;
95   }else if( sqlite3StrICmp(z, "memory")==0 ){
96     return 2;
97   }else{
98     return 0;
99   }
100 }
101 #endif /* SQLITE_PAGER_PRAGMAS */
102 
103 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
104 /*
105 ** Invalidate temp storage, either when the temp storage is changed
106 ** from default, or when 'file' and the temp_store_directory has changed
107 */
108 static int invalidateTempStorage(Parse *pParse){
109   sqlite3 *db = pParse->db;
110   if( db->aDb[1].pBt!=0 ){
111     if( !db->autoCommit || sqlite3BtreeIsInReadTrans(db->aDb[1].pBt) ){
112       sqlite3ErrorMsg(pParse, "temporary storage cannot be changed "
113         "from within a transaction");
114       return SQLITE_ERROR;
115     }
116     sqlite3BtreeClose(db->aDb[1].pBt);
117     db->aDb[1].pBt = 0;
118     sqlite3ResetInternalSchema(db, 0);
119   }
120   return SQLITE_OK;
121 }
122 #endif /* SQLITE_PAGER_PRAGMAS */
123 
124 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
125 /*
126 ** If the TEMP database is open, close it and mark the database schema
127 ** as needing reloading.  This must be done when using the SQLITE_TEMP_STORE
128 ** or DEFAULT_TEMP_STORE pragmas.
129 */
130 static int changeTempStorage(Parse *pParse, const char *zStorageType){
131   int ts = getTempStore(zStorageType);
132   sqlite3 *db = pParse->db;
133   if( db->temp_store==ts ) return SQLITE_OK;
134   if( invalidateTempStorage( pParse ) != SQLITE_OK ){
135     return SQLITE_ERROR;
136   }
137   db->temp_store = (u8)ts;
138   return SQLITE_OK;
139 }
140 #endif /* SQLITE_PAGER_PRAGMAS */
141 
142 /*
143 ** Generate code to return a single integer value.
144 */
145 static void returnSingleInt(Parse *pParse, const char *zLabel, i64 value){
146   Vdbe *v = sqlite3GetVdbe(pParse);
147   int mem = ++pParse->nMem;
148   i64 *pI64 = sqlite3DbMallocRaw(pParse->db, sizeof(value));
149   if( pI64 ){
150     memcpy(pI64, &value, sizeof(value));
151   }
152   sqlite3VdbeAddOp4(v, OP_Int64, 0, mem, 0, (char*)pI64, P4_INT64);
153   sqlite3VdbeSetNumCols(v, 1);
154   sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLabel, SQLITE_STATIC);
155   sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
156 }
157 
158 #ifndef SQLITE_OMIT_FLAG_PRAGMAS
159 /*
160 ** Check to see if zRight and zLeft refer to a pragma that queries
161 ** or changes one of the flags in db->flags.  Return 1 if so and 0 if not.
162 ** Also, implement the pragma.
163 */
164 static int flagPragma(Parse *pParse, const char *zLeft, const char *zRight){
165   static const struct sPragmaType {
166     const char *zName;  /* Name of the pragma */
167     int mask;           /* Mask for the db->flags value */
168   } aPragma[] = {
169     { "full_column_names",        SQLITE_FullColNames  },
170     { "short_column_names",       SQLITE_ShortColNames },
171     { "count_changes",            SQLITE_CountRows     },
172     { "empty_result_callbacks",   SQLITE_NullCallback  },
173     { "legacy_file_format",       SQLITE_LegacyFileFmt },
174     { "fullfsync",                SQLITE_FullFSync     },
175     { "reverse_unordered_selects", SQLITE_ReverseOrder  },
176 #ifndef SQLITE_OMIT_AUTOMATIC_INDEX
177     { "automatic_index",          SQLITE_AutoIndex     },
178 #endif
179 #ifdef SQLITE_DEBUG
180     { "sql_trace",                SQLITE_SqlTrace      },
181     { "vdbe_listing",             SQLITE_VdbeListing   },
182     { "vdbe_trace",               SQLITE_VdbeTrace     },
183 #endif
184 #ifndef SQLITE_OMIT_CHECK
185     { "ignore_check_constraints", SQLITE_IgnoreChecks  },
186 #endif
187     /* The following is VERY experimental */
188     { "writable_schema",          SQLITE_WriteSchema|SQLITE_RecoveryMode },
189     { "omit_readlock",            SQLITE_NoReadlock    },
190 
191     /* TODO: Maybe it shouldn't be possible to change the ReadUncommitted
192     ** flag if there are any active statements. */
193     { "read_uncommitted",         SQLITE_ReadUncommitted },
194     { "recursive_triggers",       SQLITE_RecTriggers },
195 
196     /* This flag may only be set if both foreign-key and trigger support
197     ** are present in the build.  */
198 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
199     { "foreign_keys",             SQLITE_ForeignKeys },
200 #endif
201   };
202   int i;
203   const struct sPragmaType *p;
204   for(i=0, p=aPragma; i<ArraySize(aPragma); i++, p++){
205     if( sqlite3StrICmp(zLeft, p->zName)==0 ){
206       sqlite3 *db = pParse->db;
207       Vdbe *v;
208       v = sqlite3GetVdbe(pParse);
209       assert( v!=0 );  /* Already allocated by sqlite3Pragma() */
210       if( ALWAYS(v) ){
211         if( zRight==0 ){
212           returnSingleInt(pParse, p->zName, (db->flags & p->mask)!=0 );
213         }else{
214           int mask = p->mask;          /* Mask of bits to set or clear. */
215           if( db->autoCommit==0 ){
216             /* Foreign key support may not be enabled or disabled while not
217             ** in auto-commit mode.  */
218             mask &= ~(SQLITE_ForeignKeys);
219           }
220 
221           if( getBoolean(zRight) ){
222             db->flags |= mask;
223           }else{
224             db->flags &= ~mask;
225           }
226 
227           /* Many of the flag-pragmas modify the code generated by the SQL
228           ** compiler (eg. count_changes). So add an opcode to expire all
229           ** compiled SQL statements after modifying a pragma value.
230           */
231           sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
232         }
233       }
234 
235       return 1;
236     }
237   }
238   return 0;
239 }
240 #endif /* SQLITE_OMIT_FLAG_PRAGMAS */
241 
242 /*
243 ** Return a human-readable name for a constraint resolution action.
244 */
245 #ifndef SQLITE_OMIT_FOREIGN_KEY
246 static const char *actionName(u8 action){
247   const char *zName;
248   switch( action ){
249     case OE_SetNull:  zName = "SET NULL";        break;
250     case OE_SetDflt:  zName = "SET DEFAULT";     break;
251     case OE_Cascade:  zName = "CASCADE";         break;
252     case OE_Restrict: zName = "RESTRICT";        break;
253     default:          zName = "NO ACTION";
254                       assert( action==OE_None ); break;
255   }
256   return zName;
257 }
258 #endif
259 
260 
261 /*
262 ** Parameter eMode must be one of the PAGER_JOURNALMODE_XXX constants
263 ** defined in pager.h. This function returns the associated lowercase
264 ** journal-mode name.
265 */
266 const char *sqlite3JournalModename(int eMode){
267   static char * const azModeName[] = {
268     "delete", "persist", "off", "truncate", "memory"
269 #ifndef SQLITE_OMIT_WAL
270      , "wal"
271 #endif
272   };
273   assert( PAGER_JOURNALMODE_DELETE==0 );
274   assert( PAGER_JOURNALMODE_PERSIST==1 );
275   assert( PAGER_JOURNALMODE_OFF==2 );
276   assert( PAGER_JOURNALMODE_TRUNCATE==3 );
277   assert( PAGER_JOURNALMODE_MEMORY==4 );
278   assert( PAGER_JOURNALMODE_WAL==5 );
279   assert( eMode>=0 && eMode<=ArraySize(azModeName) );
280 
281   if( eMode==ArraySize(azModeName) ) return 0;
282   return azModeName[eMode];
283 }
284 
285 /*
286 ** Process a pragma statement.
287 **
288 ** Pragmas are of this form:
289 **
290 **      PRAGMA [database.]id [= value]
291 **
292 ** The identifier might also be a string.  The value is a string, and
293 ** identifier, or a number.  If minusFlag is true, then the value is
294 ** a number that was preceded by a minus sign.
295 **
296 ** If the left side is "database.id" then pId1 is the database name
297 ** and pId2 is the id.  If the left side is just "id" then pId1 is the
298 ** id and pId2 is any empty string.
299 */
300 void sqlite3Pragma(
301   Parse *pParse,
302   Token *pId1,        /* First part of [database.]id field */
303   Token *pId2,        /* Second part of [database.]id field, or NULL */
304   Token *pValue,      /* Token for <value>, or NULL */
305   int minusFlag       /* True if a '-' sign preceded <value> */
306 ){
307   char *zLeft = 0;       /* Nul-terminated UTF-8 string <id> */
308   char *zRight = 0;      /* Nul-terminated UTF-8 string <value>, or NULL */
309   const char *zDb = 0;   /* The database name */
310   Token *pId;            /* Pointer to <id> token */
311   int iDb;               /* Database index for <database> */
312   sqlite3 *db = pParse->db;
313   Db *pDb;
314   Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(db);
315   if( v==0 ) return;
316   sqlite3VdbeRunOnlyOnce(v);
317   pParse->nMem = 2;
318 
319   /* Interpret the [database.] part of the pragma statement. iDb is the
320   ** index of the database this pragma is being applied to in db.aDb[]. */
321   iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
322   if( iDb<0 ) return;
323   pDb = &db->aDb[iDb];
324 
325   /* If the temp database has been explicitly named as part of the
326   ** pragma, make sure it is open.
327   */
328   if( iDb==1 && sqlite3OpenTempDatabase(pParse) ){
329     return;
330   }
331 
332   zLeft = sqlite3NameFromToken(db, pId);
333   if( !zLeft ) return;
334   if( minusFlag ){
335     zRight = sqlite3MPrintf(db, "-%T", pValue);
336   }else{
337     zRight = sqlite3NameFromToken(db, pValue);
338   }
339 
340   assert( pId2 );
341   zDb = pId2->n>0 ? pDb->zName : 0;
342   if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
343     goto pragma_out;
344   }
345 
346 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
347   /*
348   **  PRAGMA [database.]default_cache_size
349   **  PRAGMA [database.]default_cache_size=N
350   **
351   ** The first form reports the current persistent setting for the
352   ** page cache size.  The value returned is the maximum number of
353   ** pages in the page cache.  The second form sets both the current
354   ** page cache size value and the persistent page cache size value
355   ** stored in the database file.
356   **
357   ** Older versions of SQLite would set the default cache size to a
358   ** negative number to indicate synchronous=OFF.  These days, synchronous
359   ** is always on by default regardless of the sign of the default cache
360   ** size.  But continue to take the absolute value of the default cache
361   ** size of historical compatibility.
362   */
363   if( sqlite3StrICmp(zLeft,"default_cache_size")==0 ){
364     static const VdbeOpList getCacheSize[] = {
365       { OP_Transaction, 0, 0,        0},                         /* 0 */
366       { OP_ReadCookie,  0, 1,        BTREE_DEFAULT_CACHE_SIZE},  /* 1 */
367       { OP_IfPos,       1, 7,        0},
368       { OP_Integer,     0, 2,        0},
369       { OP_Subtract,    1, 2,        1},
370       { OP_IfPos,       1, 7,        0},
371       { OP_Integer,     0, 1,        0},                         /* 6 */
372       { OP_ResultRow,   1, 1,        0},
373     };
374     int addr;
375     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
376     sqlite3VdbeUsesBtree(v, iDb);
377     if( !zRight ){
378       sqlite3VdbeSetNumCols(v, 1);
379       sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", SQLITE_STATIC);
380       pParse->nMem += 2;
381       addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
382       sqlite3VdbeChangeP1(v, addr, iDb);
383       sqlite3VdbeChangeP1(v, addr+1, iDb);
384       sqlite3VdbeChangeP1(v, addr+6, SQLITE_DEFAULT_CACHE_SIZE);
385     }else{
386       int size = atoi(zRight);
387       if( size<0 ) size = -size;
388       sqlite3BeginWriteOperation(pParse, 0, iDb);
389       sqlite3VdbeAddOp2(v, OP_Integer, size, 1);
390       sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, 1);
391       pDb->pSchema->cache_size = size;
392       sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
393     }
394   }else
395 
396   /*
397   **  PRAGMA [database.]page_size
398   **  PRAGMA [database.]page_size=N
399   **
400   ** The first form reports the current setting for the
401   ** database page size in bytes.  The second form sets the
402   ** database page size value.  The value can only be set if
403   ** the database has not yet been created.
404   */
405   if( sqlite3StrICmp(zLeft,"page_size")==0 ){
406     Btree *pBt = pDb->pBt;
407     assert( pBt!=0 );
408     if( !zRight ){
409       int size = ALWAYS(pBt) ? sqlite3BtreeGetPageSize(pBt) : 0;
410       returnSingleInt(pParse, "page_size", size);
411     }else{
412       /* Malloc may fail when setting the page-size, as there is an internal
413       ** buffer that the pager module resizes using sqlite3_realloc().
414       */
415       db->nextPagesize = atoi(zRight);
416       if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1, 0) ){
417         db->mallocFailed = 1;
418       }
419     }
420   }else
421 
422   /*
423   **  PRAGMA [database.]max_page_count
424   **  PRAGMA [database.]max_page_count=N
425   **
426   ** The first form reports the current setting for the
427   ** maximum number of pages in the database file.  The
428   ** second form attempts to change this setting.  Both
429   ** forms return the current setting.
430   */
431   if( sqlite3StrICmp(zLeft,"max_page_count")==0 ){
432     Btree *pBt = pDb->pBt;
433     int newMax = 0;
434     assert( pBt!=0 );
435     if( zRight ){
436       newMax = atoi(zRight);
437     }
438     if( ALWAYS(pBt) ){
439       newMax = sqlite3BtreeMaxPageCount(pBt, newMax);
440     }
441     returnSingleInt(pParse, "max_page_count", newMax);
442   }else
443 
444   /*
445   **  PRAGMA [database.]secure_delete
446   **  PRAGMA [database.]secure_delete=ON/OFF
447   **
448   ** The first form reports the current setting for the
449   ** secure_delete flag.  The second form changes the secure_delete
450   ** flag setting and reports thenew value.
451   */
452   if( sqlite3StrICmp(zLeft,"secure_delete")==0 ){
453     Btree *pBt = pDb->pBt;
454     int b = -1;
455     assert( pBt!=0 );
456     if( zRight ){
457       b = getBoolean(zRight);
458     }
459     if( pId2->n==0 && b>=0 ){
460       int ii;
461       for(ii=0; ii<db->nDb; ii++){
462         sqlite3BtreeSecureDelete(db->aDb[ii].pBt, b);
463       }
464     }
465     b = sqlite3BtreeSecureDelete(pBt, b);
466     returnSingleInt(pParse, "secure_delete", b);
467   }else
468 
469   /*
470   **  PRAGMA [database.]page_count
471   **
472   ** Return the number of pages in the specified database.
473   */
474   if( sqlite3StrICmp(zLeft,"page_count")==0 ){
475     int iReg;
476     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
477     sqlite3CodeVerifySchema(pParse, iDb);
478     iReg = ++pParse->nMem;
479     sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg);
480     sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);
481     sqlite3VdbeSetNumCols(v, 1);
482     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "page_count", SQLITE_STATIC);
483   }else
484 
485   /*
486   **  PRAGMA [database.]locking_mode
487   **  PRAGMA [database.]locking_mode = (normal|exclusive)
488   */
489   if( sqlite3StrICmp(zLeft,"locking_mode")==0 ){
490     const char *zRet = "normal";
491     int eMode = getLockingMode(zRight);
492 
493     if( pId2->n==0 && eMode==PAGER_LOCKINGMODE_QUERY ){
494       /* Simple "PRAGMA locking_mode;" statement. This is a query for
495       ** the current default locking mode (which may be different to
496       ** the locking-mode of the main database).
497       */
498       eMode = db->dfltLockMode;
499     }else{
500       Pager *pPager;
501       if( pId2->n==0 ){
502         /* This indicates that no database name was specified as part
503         ** of the PRAGMA command. In this case the locking-mode must be
504         ** set on all attached databases, as well as the main db file.
505         **
506         ** Also, the sqlite3.dfltLockMode variable is set so that
507         ** any subsequently attached databases also use the specified
508         ** locking mode.
509         */
510         int ii;
511         assert(pDb==&db->aDb[0]);
512         for(ii=2; ii<db->nDb; ii++){
513           pPager = sqlite3BtreePager(db->aDb[ii].pBt);
514           sqlite3PagerLockingMode(pPager, eMode);
515         }
516         db->dfltLockMode = (u8)eMode;
517       }
518       pPager = sqlite3BtreePager(pDb->pBt);
519       eMode = sqlite3PagerLockingMode(pPager, eMode);
520     }
521 
522     assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE);
523     if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
524       zRet = "exclusive";
525     }
526     sqlite3VdbeSetNumCols(v, 1);
527     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", SQLITE_STATIC);
528     sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zRet, 0);
529     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
530   }else
531 
532   /*
533   **  PRAGMA [database.]journal_mode
534   **  PRAGMA [database.]journal_mode =
535   **                      (delete|persist|off|truncate|memory|wal|off)
536   */
537   if( sqlite3StrICmp(zLeft,"journal_mode")==0 ){
538     int eMode;        /* One of the PAGER_JOURNALMODE_XXX symbols */
539     int ii;           /* Loop counter */
540 
541     /* Force the schema to be loaded on all databases.  This cases all
542     ** database files to be opened and the journal_modes set. */
543     if( sqlite3ReadSchema(pParse) ){
544       goto pragma_out;
545     }
546 
547     sqlite3VdbeSetNumCols(v, 1);
548     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", SQLITE_STATIC);
549 
550     if( zRight==0 ){
551       /* If there is no "=MODE" part of the pragma, do a query for the
552       ** current mode */
553       eMode = PAGER_JOURNALMODE_QUERY;
554     }else{
555       const char *zMode;
556       int n = sqlite3Strlen30(zRight);
557       for(eMode=0; (zMode = sqlite3JournalModename(eMode))!=0; eMode++){
558         if( sqlite3StrNICmp(zRight, zMode, n)==0 ) break;
559       }
560       if( !zMode ){
561         /* If the "=MODE" part does not match any known journal mode,
562         ** then do a query */
563         eMode = PAGER_JOURNALMODE_QUERY;
564       }
565     }
566     if( eMode==PAGER_JOURNALMODE_QUERY && pId2->n==0 ){
567       /* Convert "PRAGMA journal_mode" into "PRAGMA main.journal_mode" */
568       iDb = 0;
569       pId2->n = 1;
570     }
571     for(ii=db->nDb-1; ii>=0; ii--){
572       if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
573         sqlite3VdbeUsesBtree(v, ii);
574         sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
575       }
576     }
577     sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
578   }else
579 
580   /*
581   **  PRAGMA [database.]journal_size_limit
582   **  PRAGMA [database.]journal_size_limit=N
583   **
584   ** Get or set the size limit on rollback journal files.
585   */
586   if( sqlite3StrICmp(zLeft,"journal_size_limit")==0 ){
587     Pager *pPager = sqlite3BtreePager(pDb->pBt);
588     i64 iLimit = -2;
589     if( zRight ){
590       sqlite3Atoi64(zRight, &iLimit);
591       if( iLimit<-1 ) iLimit = -1;
592     }
593     iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
594     returnSingleInt(pParse, "journal_size_limit", iLimit);
595   }else
596 
597 #endif /* SQLITE_OMIT_PAGER_PRAGMAS */
598 
599   /*
600   **  PRAGMA [database.]auto_vacuum
601   **  PRAGMA [database.]auto_vacuum=N
602   **
603   ** Get or set the value of the database 'auto-vacuum' parameter.
604   ** The value is one of:  0 NONE 1 FULL 2 INCREMENTAL
605   */
606 #ifndef SQLITE_OMIT_AUTOVACUUM
607   if( sqlite3StrICmp(zLeft,"auto_vacuum")==0 ){
608     Btree *pBt = pDb->pBt;
609     assert( pBt!=0 );
610     if( sqlite3ReadSchema(pParse) ){
611       goto pragma_out;
612     }
613     if( !zRight ){
614       int auto_vacuum;
615       if( ALWAYS(pBt) ){
616          auto_vacuum = sqlite3BtreeGetAutoVacuum(pBt);
617       }else{
618          auto_vacuum = SQLITE_DEFAULT_AUTOVACUUM;
619       }
620       returnSingleInt(pParse, "auto_vacuum", auto_vacuum);
621     }else{
622       int eAuto = getAutoVacuum(zRight);
623       assert( eAuto>=0 && eAuto<=2 );
624       db->nextAutovac = (u8)eAuto;
625       if( ALWAYS(eAuto>=0) ){
626         /* Call SetAutoVacuum() to set initialize the internal auto and
627         ** incr-vacuum flags. This is required in case this connection
628         ** creates the database file. It is important that it is created
629         ** as an auto-vacuum capable db.
630         */
631         int rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
632         if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
633           /* When setting the auto_vacuum mode to either "full" or
634           ** "incremental", write the value of meta[6] in the database
635           ** file. Before writing to meta[6], check that meta[3] indicates
636           ** that this really is an auto-vacuum capable database.
637           */
638           static const VdbeOpList setMeta6[] = {
639             { OP_Transaction,    0,         1,                 0},    /* 0 */
640             { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},
641             { OP_If,             1,         0,                 0},    /* 2 */
642             { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */
643             { OP_Integer,        0,         1,                 0},    /* 4 */
644             { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 1},    /* 5 */
645           };
646           int iAddr;
647           iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6);
648           sqlite3VdbeChangeP1(v, iAddr, iDb);
649           sqlite3VdbeChangeP1(v, iAddr+1, iDb);
650           sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4);
651           sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1);
652           sqlite3VdbeChangeP1(v, iAddr+5, iDb);
653           sqlite3VdbeUsesBtree(v, iDb);
654         }
655       }
656     }
657   }else
658 #endif
659 
660   /*
661   **  PRAGMA [database.]incremental_vacuum(N)
662   **
663   ** Do N steps of incremental vacuuming on a database.
664   */
665 #ifndef SQLITE_OMIT_AUTOVACUUM
666   if( sqlite3StrICmp(zLeft,"incremental_vacuum")==0 ){
667     int iLimit, addr;
668     if( sqlite3ReadSchema(pParse) ){
669       goto pragma_out;
670     }
671     if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
672       iLimit = 0x7fffffff;
673     }
674     sqlite3BeginWriteOperation(pParse, 0, iDb);
675     sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);
676     addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb);
677     sqlite3VdbeAddOp1(v, OP_ResultRow, 1);
678     sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
679     sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr);
680     sqlite3VdbeJumpHere(v, addr);
681   }else
682 #endif
683 
684 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
685   /*
686   **  PRAGMA [database.]cache_size
687   **  PRAGMA [database.]cache_size=N
688   **
689   ** The first form reports the current local setting for the
690   ** page cache size.  The local setting can be different from
691   ** the persistent cache size value that is stored in the database
692   ** file itself.  The value returned is the maximum number of
693   ** pages in the page cache.  The second form sets the local
694   ** page cache size value.  It does not change the persistent
695   ** cache size stored on the disk so the cache size will revert
696   ** to its default value when the database is closed and reopened.
697   ** N should be a positive integer.
698   */
699   if( sqlite3StrICmp(zLeft,"cache_size")==0 ){
700     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
701     if( !zRight ){
702       returnSingleInt(pParse, "cache_size", pDb->pSchema->cache_size);
703     }else{
704       int size = atoi(zRight);
705       if( size<0 ) size = -size;
706       pDb->pSchema->cache_size = size;
707       sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
708     }
709   }else
710 
711   /*
712   **   PRAGMA temp_store
713   **   PRAGMA temp_store = "default"|"memory"|"file"
714   **
715   ** Return or set the local value of the temp_store flag.  Changing
716   ** the local value does not make changes to the disk file and the default
717   ** value will be restored the next time the database is opened.
718   **
719   ** Note that it is possible for the library compile-time options to
720   ** override this setting
721   */
722   if( sqlite3StrICmp(zLeft, "temp_store")==0 ){
723     if( !zRight ){
724       returnSingleInt(pParse, "temp_store", db->temp_store);
725     }else{
726       changeTempStorage(pParse, zRight);
727     }
728   }else
729 
730   /*
731   **   PRAGMA temp_store_directory
732   **   PRAGMA temp_store_directory = ""|"directory_name"
733   **
734   ** Return or set the local value of the temp_store_directory flag.  Changing
735   ** the value sets a specific directory to be used for temporary files.
736   ** Setting to a null string reverts to the default temporary directory search.
737   ** If temporary directory is changed, then invalidateTempStorage.
738   **
739   */
740   if( sqlite3StrICmp(zLeft, "temp_store_directory")==0 ){
741     if( !zRight ){
742       if( sqlite3_temp_directory ){
743         sqlite3VdbeSetNumCols(v, 1);
744         sqlite3VdbeSetColName(v, 0, COLNAME_NAME,
745             "temp_store_directory", SQLITE_STATIC);
746         sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0);
747         sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
748       }
749     }else{
750 #ifndef SQLITE_OMIT_WSD
751       if( zRight[0] ){
752         int rc;
753         int res;
754         rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
755         if( rc!=SQLITE_OK || res==0 ){
756           sqlite3ErrorMsg(pParse, "not a writable directory");
757           goto pragma_out;
758         }
759       }
760       if( SQLITE_TEMP_STORE==0
761        || (SQLITE_TEMP_STORE==1 && db->temp_store<=1)
762        || (SQLITE_TEMP_STORE==2 && db->temp_store==1)
763       ){
764         invalidateTempStorage(pParse);
765       }
766       sqlite3_free(sqlite3_temp_directory);
767       if( zRight[0] ){
768         sqlite3_temp_directory = sqlite3_mprintf("%s", zRight);
769       }else{
770         sqlite3_temp_directory = 0;
771       }
772 #endif /* SQLITE_OMIT_WSD */
773     }
774   }else
775 
776 #if !defined(SQLITE_ENABLE_LOCKING_STYLE)
777 #  if defined(__APPLE__)
778 #    define SQLITE_ENABLE_LOCKING_STYLE 1
779 #  else
780 #    define SQLITE_ENABLE_LOCKING_STYLE 0
781 #  endif
782 #endif
783 #if SQLITE_ENABLE_LOCKING_STYLE
784   /*
785    **   PRAGMA [database.]lock_proxy_file
786    **   PRAGMA [database.]lock_proxy_file = ":auto:"|"lock_file_path"
787    **
788    ** Return or set the value of the lock_proxy_file flag.  Changing
789    ** the value sets a specific file to be used for database access locks.
790    **
791    */
792   if( sqlite3StrICmp(zLeft, "lock_proxy_file")==0 ){
793     if( !zRight ){
794       Pager *pPager = sqlite3BtreePager(pDb->pBt);
795       char *proxy_file_path = NULL;
796       sqlite3_file *pFile = sqlite3PagerFile(pPager);
797       sqlite3OsFileControl(pFile, SQLITE_GET_LOCKPROXYFILE,
798                            &proxy_file_path);
799 
800       if( proxy_file_path ){
801         sqlite3VdbeSetNumCols(v, 1);
802         sqlite3VdbeSetColName(v, 0, COLNAME_NAME,
803                               "lock_proxy_file", SQLITE_STATIC);
804         sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, proxy_file_path, 0);
805         sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
806       }
807     }else{
808       Pager *pPager = sqlite3BtreePager(pDb->pBt);
809       sqlite3_file *pFile = sqlite3PagerFile(pPager);
810       int res;
811       if( zRight[0] ){
812         res=sqlite3OsFileControl(pFile, SQLITE_SET_LOCKPROXYFILE,
813                                      zRight);
814       } else {
815         res=sqlite3OsFileControl(pFile, SQLITE_SET_LOCKPROXYFILE,
816                                      NULL);
817       }
818       if( res!=SQLITE_OK ){
819         sqlite3ErrorMsg(pParse, "failed to set lock proxy file");
820         goto pragma_out;
821       }
822     }
823   }else
824 #endif /* SQLITE_ENABLE_LOCKING_STYLE */
825 
826   /*
827   **   PRAGMA [database.]synchronous
828   **   PRAGMA [database.]synchronous=OFF|ON|NORMAL|FULL
829   **
830   ** Return or set the local value of the synchronous flag.  Changing
831   ** the local value does not make changes to the disk file and the
832   ** default value will be restored the next time the database is
833   ** opened.
834   */
835   if( sqlite3StrICmp(zLeft,"synchronous")==0 ){
836     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
837     if( !zRight ){
838       returnSingleInt(pParse, "synchronous", pDb->safety_level-1);
839     }else{
840       if( !db->autoCommit ){
841         sqlite3ErrorMsg(pParse,
842             "Safety level may not be changed inside a transaction");
843       }else{
844         pDb->safety_level = getSafetyLevel(zRight)+1;
845       }
846     }
847   }else
848 #endif /* SQLITE_OMIT_PAGER_PRAGMAS */
849 
850 #ifndef SQLITE_OMIT_FLAG_PRAGMAS
851   if( flagPragma(pParse, zLeft, zRight) ){
852     /* The flagPragma() subroutine also generates any necessary code
853     ** there is nothing more to do here */
854   }else
855 #endif /* SQLITE_OMIT_FLAG_PRAGMAS */
856 
857 #ifndef SQLITE_OMIT_SCHEMA_PRAGMAS
858   /*
859   **   PRAGMA table_info(<table>)
860   **
861   ** Return a single row for each column of the named table. The columns of
862   ** the returned data set are:
863   **
864   ** cid:        Column id (numbered from left to right, starting at 0)
865   ** name:       Column name
866   ** type:       Column declaration type.
867   ** notnull:    True if 'NOT NULL' is part of column declaration
868   ** dflt_value: The default value for the column, if any.
869   */
870   if( sqlite3StrICmp(zLeft, "table_info")==0 && zRight ){
871     Table *pTab;
872     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
873     pTab = sqlite3FindTable(db, zRight, zDb);
874     if( pTab ){
875       int i;
876       int nHidden = 0;
877       Column *pCol;
878       sqlite3VdbeSetNumCols(v, 6);
879       pParse->nMem = 6;
880       sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", SQLITE_STATIC);
881       sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
882       sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", SQLITE_STATIC);
883       sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", SQLITE_STATIC);
884       sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", SQLITE_STATIC);
885       sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", SQLITE_STATIC);
886       sqlite3ViewGetColumnNames(pParse, pTab);
887       for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
888         if( IsHiddenColumn(pCol) ){
889           nHidden++;
890           continue;
891         }
892         sqlite3VdbeAddOp2(v, OP_Integer, i-nHidden, 1);
893         sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pCol->zName, 0);
894         sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
895            pCol->zType ? pCol->zType : "", 0);
896         sqlite3VdbeAddOp2(v, OP_Integer, (pCol->notNull ? 1 : 0), 4);
897         if( pCol->zDflt ){
898           sqlite3VdbeAddOp4(v, OP_String8, 0, 5, 0, (char*)pCol->zDflt, 0);
899         }else{
900           sqlite3VdbeAddOp2(v, OP_Null, 0, 5);
901         }
902         sqlite3VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 6);
903         sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 6);
904       }
905     }
906   }else
907 
908   if( sqlite3StrICmp(zLeft, "index_info")==0 && zRight ){
909     Index *pIdx;
910     Table *pTab;
911     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
912     pIdx = sqlite3FindIndex(db, zRight, zDb);
913     if( pIdx ){
914       int i;
915       pTab = pIdx->pTable;
916       sqlite3VdbeSetNumCols(v, 3);
917       pParse->nMem = 3;
918       sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", SQLITE_STATIC);
919       sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", SQLITE_STATIC);
920       sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", SQLITE_STATIC);
921       for(i=0; i<pIdx->nColumn; i++){
922         int cnum = pIdx->aiColumn[i];
923         sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
924         sqlite3VdbeAddOp2(v, OP_Integer, cnum, 2);
925         assert( pTab->nCol>cnum );
926         sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pTab->aCol[cnum].zName, 0);
927         sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
928       }
929     }
930   }else
931 
932   if( sqlite3StrICmp(zLeft, "index_list")==0 && zRight ){
933     Index *pIdx;
934     Table *pTab;
935     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
936     pTab = sqlite3FindTable(db, zRight, zDb);
937     if( pTab ){
938       v = sqlite3GetVdbe(pParse);
939       pIdx = pTab->pIndex;
940       if( pIdx ){
941         int i = 0;
942         sqlite3VdbeSetNumCols(v, 3);
943         pParse->nMem = 3;
944         sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
945         sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
946         sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", SQLITE_STATIC);
947         while(pIdx){
948           sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
949           sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0);
950           sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3);
951           sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
952           ++i;
953           pIdx = pIdx->pNext;
954         }
955       }
956     }
957   }else
958 
959   if( sqlite3StrICmp(zLeft, "database_list")==0 ){
960     int i;
961     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
962     sqlite3VdbeSetNumCols(v, 3);
963     pParse->nMem = 3;
964     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
965     sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
966     sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", SQLITE_STATIC);
967     for(i=0; i<db->nDb; i++){
968       if( db->aDb[i].pBt==0 ) continue;
969       assert( db->aDb[i].zName!=0 );
970       sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
971       sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0);
972       sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
973            sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
974       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
975     }
976   }else
977 
978   if( sqlite3StrICmp(zLeft, "collation_list")==0 ){
979     int i = 0;
980     HashElem *p;
981     sqlite3VdbeSetNumCols(v, 2);
982     pParse->nMem = 2;
983     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", SQLITE_STATIC);
984     sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", SQLITE_STATIC);
985     for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
986       CollSeq *pColl = (CollSeq *)sqliteHashData(p);
987       sqlite3VdbeAddOp2(v, OP_Integer, i++, 1);
988       sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pColl->zName, 0);
989       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
990     }
991   }else
992 #endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */
993 
994 #ifndef SQLITE_OMIT_FOREIGN_KEY
995   if( sqlite3StrICmp(zLeft, "foreign_key_list")==0 && zRight ){
996     FKey *pFK;
997     Table *pTab;
998     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
999     pTab = sqlite3FindTable(db, zRight, zDb);
1000     if( pTab ){
1001       v = sqlite3GetVdbe(pParse);
1002       pFK = pTab->pFKey;
1003       if( pFK ){
1004         int i = 0;
1005         sqlite3VdbeSetNumCols(v, 8);
1006         pParse->nMem = 8;
1007         sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", SQLITE_STATIC);
1008         sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", SQLITE_STATIC);
1009         sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", SQLITE_STATIC);
1010         sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", SQLITE_STATIC);
1011         sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", SQLITE_STATIC);
1012         sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "on_update", SQLITE_STATIC);
1013         sqlite3VdbeSetColName(v, 6, COLNAME_NAME, "on_delete", SQLITE_STATIC);
1014         sqlite3VdbeSetColName(v, 7, COLNAME_NAME, "match", SQLITE_STATIC);
1015         while(pFK){
1016           int j;
1017           for(j=0; j<pFK->nCol; j++){
1018             char *zCol = pFK->aCol[j].zCol;
1019             char *zOnDelete = (char *)actionName(pFK->aAction[0]);
1020             char *zOnUpdate = (char *)actionName(pFK->aAction[1]);
1021             sqlite3VdbeAddOp2(v, OP_Integer, i, 1);
1022             sqlite3VdbeAddOp2(v, OP_Integer, j, 2);
1023             sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pFK->zTo, 0);
1024             sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0,
1025                               pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
1026             sqlite3VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 5, 0, zCol, 0);
1027             sqlite3VdbeAddOp4(v, OP_String8, 0, 6, 0, zOnUpdate, 0);
1028             sqlite3VdbeAddOp4(v, OP_String8, 0, 7, 0, zOnDelete, 0);
1029             sqlite3VdbeAddOp4(v, OP_String8, 0, 8, 0, "NONE", 0);
1030             sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 8);
1031           }
1032           ++i;
1033           pFK = pFK->pNextFrom;
1034         }
1035       }
1036     }
1037   }else
1038 #endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
1039 
1040 #ifndef NDEBUG
1041   if( sqlite3StrICmp(zLeft, "parser_trace")==0 ){
1042     if( zRight ){
1043       if( getBoolean(zRight) ){
1044         sqlite3ParserTrace(stderr, "parser: ");
1045       }else{
1046         sqlite3ParserTrace(0, 0);
1047       }
1048     }
1049   }else
1050 #endif
1051 
1052   /* Reinstall the LIKE and GLOB functions.  The variant of LIKE
1053   ** used will be case sensitive or not depending on the RHS.
1054   */
1055   if( sqlite3StrICmp(zLeft, "case_sensitive_like")==0 ){
1056     if( zRight ){
1057       sqlite3RegisterLikeFunctions(db, getBoolean(zRight));
1058     }
1059   }else
1060 
1061 #ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
1062 # define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
1063 #endif
1064 
1065 #ifndef SQLITE_OMIT_INTEGRITY_CHECK
1066   /* Pragma "quick_check" is an experimental reduced version of
1067   ** integrity_check designed to detect most database corruption
1068   ** without most of the overhead of a full integrity-check.
1069   */
1070   if( sqlite3StrICmp(zLeft, "integrity_check")==0
1071    || sqlite3StrICmp(zLeft, "quick_check")==0
1072   ){
1073     int i, j, addr, mxErr;
1074 
1075     /* Code that appears at the end of the integrity check.  If no error
1076     ** messages have been generated, output OK.  Otherwise output the
1077     ** error message
1078     */
1079     static const VdbeOpList endCode[] = {
1080       { OP_AddImm,      1, 0,        0},    /* 0 */
1081       { OP_IfNeg,       1, 0,        0},    /* 1 */
1082       { OP_String8,     0, 3,        0},    /* 2 */
1083       { OP_ResultRow,   3, 1,        0},
1084     };
1085 
1086     int isQuick = (zLeft[0]=='q');
1087 
1088     /* Initialize the VDBE program */
1089     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
1090     pParse->nMem = 6;
1091     sqlite3VdbeSetNumCols(v, 1);
1092     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", SQLITE_STATIC);
1093 
1094     /* Set the maximum error count */
1095     mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
1096     if( zRight ){
1097       mxErr = atoi(zRight);
1098       if( mxErr<=0 ){
1099         mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
1100       }
1101     }
1102     sqlite3VdbeAddOp2(v, OP_Integer, mxErr, 1);  /* reg[1] holds errors left */
1103 
1104     /* Do an integrity check on each database file */
1105     for(i=0; i<db->nDb; i++){
1106       HashElem *x;
1107       Hash *pTbls;
1108       int cnt = 0;
1109 
1110       if( OMIT_TEMPDB && i==1 ) continue;
1111 
1112       sqlite3CodeVerifySchema(pParse, i);
1113       addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Halt if out of errors */
1114       sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
1115       sqlite3VdbeJumpHere(v, addr);
1116 
1117       /* Do an integrity check of the B-Tree
1118       **
1119       ** Begin by filling registers 2, 3, ... with the root pages numbers
1120       ** for all tables and indices in the database.
1121       */
1122       pTbls = &db->aDb[i].pSchema->tblHash;
1123       for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
1124         Table *pTab = sqliteHashData(x);
1125         Index *pIdx;
1126         sqlite3VdbeAddOp2(v, OP_Integer, pTab->tnum, 2+cnt);
1127         cnt++;
1128         for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
1129           sqlite3VdbeAddOp2(v, OP_Integer, pIdx->tnum, 2+cnt);
1130           cnt++;
1131         }
1132       }
1133 
1134       /* Make sure sufficient number of registers have been allocated */
1135       if( pParse->nMem < cnt+4 ){
1136         pParse->nMem = cnt+4;
1137       }
1138 
1139       /* Do the b-tree integrity checks */
1140       sqlite3VdbeAddOp3(v, OP_IntegrityCk, 2, cnt, 1);
1141       sqlite3VdbeChangeP5(v, (u8)i);
1142       addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2);
1143       sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
1144          sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
1145          P4_DYNAMIC);
1146       sqlite3VdbeAddOp3(v, OP_Move, 2, 4, 1);
1147       sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 2);
1148       sqlite3VdbeAddOp2(v, OP_ResultRow, 2, 1);
1149       sqlite3VdbeJumpHere(v, addr);
1150 
1151       /* Make sure all the indices are constructed correctly.
1152       */
1153       for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){
1154         Table *pTab = sqliteHashData(x);
1155         Index *pIdx;
1156         int loopTop;
1157 
1158         if( pTab->pIndex==0 ) continue;
1159         addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);  /* Stop if out of errors */
1160         sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
1161         sqlite3VdbeJumpHere(v, addr);
1162         sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
1163         sqlite3VdbeAddOp2(v, OP_Integer, 0, 2);  /* reg(2) will count entries */
1164         loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0);
1165         sqlite3VdbeAddOp2(v, OP_AddImm, 2, 1);   /* increment entry count */
1166         for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
1167           int jmp2;
1168           int r1;
1169           static const VdbeOpList idxErr[] = {
1170             { OP_AddImm,      1, -1,  0},
1171             { OP_String8,     0,  3,  0},    /* 1 */
1172             { OP_Rowid,       1,  4,  0},
1173             { OP_String8,     0,  5,  0},    /* 3 */
1174             { OP_String8,     0,  6,  0},    /* 4 */
1175             { OP_Concat,      4,  3,  3},
1176             { OP_Concat,      5,  3,  3},
1177             { OP_Concat,      6,  3,  3},
1178             { OP_ResultRow,   3,  1,  0},
1179             { OP_IfPos,       1,  0,  0},    /* 9 */
1180             { OP_Halt,        0,  0,  0},
1181           };
1182           r1 = sqlite3GenerateIndexKey(pParse, pIdx, 1, 3, 0);
1183           jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, j+2, 0, r1, pIdx->nColumn+1);
1184           addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
1185           sqlite3VdbeChangeP4(v, addr+1, "rowid ", P4_STATIC);
1186           sqlite3VdbeChangeP4(v, addr+3, " missing from index ", P4_STATIC);
1187           sqlite3VdbeChangeP4(v, addr+4, pIdx->zName, P4_STATIC);
1188           sqlite3VdbeJumpHere(v, addr+9);
1189           sqlite3VdbeJumpHere(v, jmp2);
1190         }
1191         sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop+1);
1192         sqlite3VdbeJumpHere(v, loopTop);
1193         for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
1194           static const VdbeOpList cntIdx[] = {
1195              { OP_Integer,      0,  3,  0},
1196              { OP_Rewind,       0,  0,  0},  /* 1 */
1197              { OP_AddImm,       3,  1,  0},
1198              { OP_Next,         0,  0,  0},  /* 3 */
1199              { OP_Eq,           2,  0,  3},  /* 4 */
1200              { OP_AddImm,       1, -1,  0},
1201              { OP_String8,      0,  2,  0},  /* 6 */
1202              { OP_String8,      0,  3,  0},  /* 7 */
1203              { OP_Concat,       3,  2,  2},
1204              { OP_ResultRow,    2,  1,  0},
1205           };
1206           addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);
1207           sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
1208           sqlite3VdbeJumpHere(v, addr);
1209           addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
1210           sqlite3VdbeChangeP1(v, addr+1, j+2);
1211           sqlite3VdbeChangeP2(v, addr+1, addr+4);
1212           sqlite3VdbeChangeP1(v, addr+3, j+2);
1213           sqlite3VdbeChangeP2(v, addr+3, addr+2);
1214           sqlite3VdbeJumpHere(v, addr+4);
1215           sqlite3VdbeChangeP4(v, addr+6,
1216                      "wrong # of entries in index ", P4_STATIC);
1217           sqlite3VdbeChangeP4(v, addr+7, pIdx->zName, P4_STATIC);
1218         }
1219       }
1220     }
1221     addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
1222     sqlite3VdbeChangeP2(v, addr, -mxErr);
1223     sqlite3VdbeJumpHere(v, addr+1);
1224     sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC);
1225   }else
1226 #endif /* SQLITE_OMIT_INTEGRITY_CHECK */
1227 
1228 #ifndef SQLITE_OMIT_UTF16
1229   /*
1230   **   PRAGMA encoding
1231   **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"
1232   **
1233   ** In its first form, this pragma returns the encoding of the main
1234   ** database. If the database is not initialized, it is initialized now.
1235   **
1236   ** The second form of this pragma is a no-op if the main database file
1237   ** has not already been initialized. In this case it sets the default
1238   ** encoding that will be used for the main database file if a new file
1239   ** is created. If an existing main database file is opened, then the
1240   ** default text encoding for the existing database is used.
1241   **
1242   ** In all cases new databases created using the ATTACH command are
1243   ** created to use the same default text encoding as the main database. If
1244   ** the main database has not been initialized and/or created when ATTACH
1245   ** is executed, this is done before the ATTACH operation.
1246   **
1247   ** In the second form this pragma sets the text encoding to be used in
1248   ** new database files created using this database handle. It is only
1249   ** useful if invoked immediately after the main database i
1250   */
1251   if( sqlite3StrICmp(zLeft, "encoding")==0 ){
1252     static const struct EncName {
1253       char *zName;
1254       u8 enc;
1255     } encnames[] = {
1256       { "UTF8",     SQLITE_UTF8        },
1257       { "UTF-8",    SQLITE_UTF8        },  /* Must be element [1] */
1258       { "UTF-16le", SQLITE_UTF16LE     },  /* Must be element [2] */
1259       { "UTF-16be", SQLITE_UTF16BE     },  /* Must be element [3] */
1260       { "UTF16le",  SQLITE_UTF16LE     },
1261       { "UTF16be",  SQLITE_UTF16BE     },
1262       { "UTF-16",   0                  }, /* SQLITE_UTF16NATIVE */
1263       { "UTF16",    0                  }, /* SQLITE_UTF16NATIVE */
1264       { 0, 0 }
1265     };
1266     const struct EncName *pEnc;
1267     if( !zRight ){    /* "PRAGMA encoding" */
1268       if( sqlite3ReadSchema(pParse) ) goto pragma_out;
1269       sqlite3VdbeSetNumCols(v, 1);
1270       sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", SQLITE_STATIC);
1271       sqlite3VdbeAddOp2(v, OP_String8, 0, 1);
1272       assert( encnames[SQLITE_UTF8].enc==SQLITE_UTF8 );
1273       assert( encnames[SQLITE_UTF16LE].enc==SQLITE_UTF16LE );
1274       assert( encnames[SQLITE_UTF16BE].enc==SQLITE_UTF16BE );
1275       sqlite3VdbeChangeP4(v, -1, encnames[ENC(pParse->db)].zName, P4_STATIC);
1276       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1277     }else{                        /* "PRAGMA encoding = XXX" */
1278       /* Only change the value of sqlite.enc if the database handle is not
1279       ** initialized. If the main database exists, the new sqlite.enc value
1280       ** will be overwritten when the schema is next loaded. If it does not
1281       ** already exists, it will be created to use the new encoding value.
1282       */
1283       if(
1284         !(DbHasProperty(db, 0, DB_SchemaLoaded)) ||
1285         DbHasProperty(db, 0, DB_Empty)
1286       ){
1287         for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
1288           if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){
1289             ENC(pParse->db) = pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
1290             break;
1291           }
1292         }
1293         if( !pEnc->zName ){
1294           sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);
1295         }
1296       }
1297     }
1298   }else
1299 #endif /* SQLITE_OMIT_UTF16 */
1300 
1301 #ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
1302   /*
1303   **   PRAGMA [database.]schema_version
1304   **   PRAGMA [database.]schema_version = <integer>
1305   **
1306   **   PRAGMA [database.]user_version
1307   **   PRAGMA [database.]user_version = <integer>
1308   **
1309   ** The pragma's schema_version and user_version are used to set or get
1310   ** the value of the schema-version and user-version, respectively. Both
1311   ** the schema-version and the user-version are 32-bit signed integers
1312   ** stored in the database header.
1313   **
1314   ** The schema-cookie is usually only manipulated internally by SQLite. It
1315   ** is incremented by SQLite whenever the database schema is modified (by
1316   ** creating or dropping a table or index). The schema version is used by
1317   ** SQLite each time a query is executed to ensure that the internal cache
1318   ** of the schema used when compiling the SQL query matches the schema of
1319   ** the database against which the compiled query is actually executed.
1320   ** Subverting this mechanism by using "PRAGMA schema_version" to modify
1321   ** the schema-version is potentially dangerous and may lead to program
1322   ** crashes or database corruption. Use with caution!
1323   **
1324   ** The user-version is not used internally by SQLite. It may be used by
1325   ** applications for any purpose.
1326   */
1327   if( sqlite3StrICmp(zLeft, "schema_version")==0
1328    || sqlite3StrICmp(zLeft, "user_version")==0
1329    || sqlite3StrICmp(zLeft, "freelist_count")==0
1330   ){
1331     int iCookie;   /* Cookie index. 1 for schema-cookie, 6 for user-cookie. */
1332     sqlite3VdbeUsesBtree(v, iDb);
1333     switch( zLeft[0] ){
1334       case 'f': case 'F':
1335         iCookie = BTREE_FREE_PAGE_COUNT;
1336         break;
1337       case 's': case 'S':
1338         iCookie = BTREE_SCHEMA_VERSION;
1339         break;
1340       default:
1341         iCookie = BTREE_USER_VERSION;
1342         break;
1343     }
1344 
1345     if( zRight && iCookie!=BTREE_FREE_PAGE_COUNT ){
1346       /* Write the specified cookie value */
1347       static const VdbeOpList setCookie[] = {
1348         { OP_Transaction,    0,  1,  0},    /* 0 */
1349         { OP_Integer,        0,  1,  0},    /* 1 */
1350         { OP_SetCookie,      0,  0,  1},    /* 2 */
1351       };
1352       int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie);
1353       sqlite3VdbeChangeP1(v, addr, iDb);
1354       sqlite3VdbeChangeP1(v, addr+1, atoi(zRight));
1355       sqlite3VdbeChangeP1(v, addr+2, iDb);
1356       sqlite3VdbeChangeP2(v, addr+2, iCookie);
1357     }else{
1358       /* Read the specified cookie value */
1359       static const VdbeOpList readCookie[] = {
1360         { OP_Transaction,     0,  0,  0},    /* 0 */
1361         { OP_ReadCookie,      0,  1,  0},    /* 1 */
1362         { OP_ResultRow,       1,  1,  0}
1363       };
1364       int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
1365       sqlite3VdbeChangeP1(v, addr, iDb);
1366       sqlite3VdbeChangeP1(v, addr+1, iDb);
1367       sqlite3VdbeChangeP3(v, addr+1, iCookie);
1368       sqlite3VdbeSetNumCols(v, 1);
1369       sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, SQLITE_TRANSIENT);
1370     }
1371   }else
1372 #endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */
1373 
1374 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
1375   /*
1376   **   PRAGMA compile_options
1377   **
1378   ** Return the names of all compile-time options used in this build,
1379   ** one option per row.
1380   */
1381   if( sqlite3StrICmp(zLeft, "compile_options")==0 ){
1382     int i = 0;
1383     const char *zOpt;
1384     sqlite3VdbeSetNumCols(v, 1);
1385     pParse->nMem = 1;
1386     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "compile_option", SQLITE_STATIC);
1387     while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){
1388       sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zOpt, 0);
1389       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
1390     }
1391   }else
1392 #endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
1393 
1394 #ifndef SQLITE_OMIT_WAL
1395   /*
1396   **   PRAGMA [database.]wal_checkpoint
1397   **
1398   ** Checkpoint the database.
1399   */
1400   if( sqlite3StrICmp(zLeft, "wal_checkpoint")==0 ){
1401     if( sqlite3ReadSchema(pParse) ) goto pragma_out;
1402     sqlite3VdbeAddOp3(v, OP_Checkpoint, pId2->z?iDb:SQLITE_MAX_ATTACHED, 0, 0);
1403   }else
1404 
1405   /*
1406   **   PRAGMA wal_autocheckpoint
1407   **   PRAGMA wal_autocheckpoint = N
1408   **
1409   ** Configure a database connection to automatically checkpoint a database
1410   ** after accumulating N frames in the log. Or query for the current value
1411   ** of N.
1412   */
1413   if( sqlite3StrICmp(zLeft, "wal_autocheckpoint")==0 ){
1414     if( zRight ){
1415       int nAuto = atoi(zRight);
1416       sqlite3_wal_autocheckpoint(db, nAuto);
1417     }
1418     returnSingleInt(pParse, "wal_autocheckpoint",
1419        db->xWalCallback==sqlite3WalDefaultHook ?
1420            SQLITE_PTR_TO_INT(db->pWalArg) : 0);
1421   }else
1422 #endif
1423 
1424 #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
1425   /*
1426   ** Report the current state of file logs for all databases
1427   */
1428   if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
1429     static const char *const azLockName[] = {
1430       "unlocked", "shared", "reserved", "pending", "exclusive"
1431     };
1432     int i;
1433     sqlite3VdbeSetNumCols(v, 2);
1434     pParse->nMem = 2;
1435     sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", SQLITE_STATIC);
1436     sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", SQLITE_STATIC);
1437     for(i=0; i<db->nDb; i++){
1438       Btree *pBt;
1439       Pager *pPager;
1440       const char *zState = "unknown";
1441       int j;
1442       if( db->aDb[i].zName==0 ) continue;
1443       sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, db->aDb[i].zName, P4_STATIC);
1444       pBt = db->aDb[i].pBt;
1445       if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
1446         zState = "closed";
1447       }else if( sqlite3_file_control(db, i ? db->aDb[i].zName : 0,
1448                                      SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
1449          zState = azLockName[j];
1450       }
1451       sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, zState, P4_STATIC);
1452       sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2);
1453     }
1454 
1455   }else
1456 #endif
1457 
1458 #ifdef SQLITE_HAS_CODEC
1459   if( sqlite3StrICmp(zLeft, "key")==0 && zRight ){
1460     sqlite3_key(db, zRight, sqlite3Strlen30(zRight));
1461   }else
1462   if( sqlite3StrICmp(zLeft, "rekey")==0 && zRight ){
1463     sqlite3_rekey(db, zRight, sqlite3Strlen30(zRight));
1464   }else
1465   if( zRight && (sqlite3StrICmp(zLeft, "hexkey")==0 ||
1466                  sqlite3StrICmp(zLeft, "hexrekey")==0) ){
1467     int i, h1, h2;
1468     char zKey[40];
1469     for(i=0; (h1 = zRight[i])!=0 && (h2 = zRight[i+1])!=0; i+=2){
1470       h1 += 9*(1&(h1>>6));
1471       h2 += 9*(1&(h2>>6));
1472       zKey[i/2] = (h2 & 0x0f) | ((h1 & 0xf)<<4);
1473     }
1474     if( (zLeft[3] & 0xf)==0xb ){
1475       sqlite3_key(db, zKey, i/2);
1476     }else{
1477       sqlite3_rekey(db, zKey, i/2);
1478     }
1479   }else
1480 #endif
1481 #if defined(SQLITE_HAS_CODEC) || defined(SQLITE_ENABLE_CEROD)
1482   if( sqlite3StrICmp(zLeft, "activate_extensions")==0 ){
1483 #ifdef SQLITE_HAS_CODEC
1484     if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){
1485       sqlite3_activate_see(&zRight[4]);
1486     }
1487 #endif
1488 #ifdef SQLITE_ENABLE_CEROD
1489     if( sqlite3StrNICmp(zRight, "cerod-", 6)==0 ){
1490       sqlite3_activate_cerod(&zRight[6]);
1491     }
1492 #endif
1493   }else
1494 #endif
1495 
1496 
1497   {/* Empty ELSE clause */}
1498 
1499   /*
1500   ** Reset the safety level, in case the fullfsync flag or synchronous
1501   ** setting changed.
1502   */
1503 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
1504   if( db->autoCommit ){
1505     sqlite3BtreeSetSafetyLevel(pDb->pBt, pDb->safety_level,
1506                (db->flags&SQLITE_FullFSync)!=0);
1507   }
1508 #endif
1509 pragma_out:
1510   sqlite3DbFree(db, zLeft);
1511   sqlite3DbFree(db, zRight);
1512 }
1513 
1514 #endif /* SQLITE_OMIT_PRAGMA */
1515