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| 1 /* | |
| 2 ** 2005 July 8 | |
| 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 associated with the ANALYZE command. | |
| 13 ** | |
| 14 ** @(#) $Id: analyze.c,v 1.52 2009/04/16 17:45:48 drh Exp $ | |
| 15 */ | |
| 16 #ifndef SQLITE_OMIT_ANALYZE | |
| 17 #include "sqliteInt.h" | |
| 18 | |
| 19 /* | |
| 20 ** This routine generates code that opens the sqlite_stat1 table for | |
| 21 ** writing with cursor iStatCur. If the library was built with the | |
| 22 ** SQLITE_ENABLE_STAT2 macro defined, then the sqlite_stat2 table is | |
| 23 ** opened for writing using cursor (iStatCur+1) | |
| 24 ** | |
| 25 ** If the sqlite_stat1 tables does not previously exist, it is created. | |
| 26 ** Similarly, if the sqlite_stat2 table does not exist and the library | |
| 27 ** is compiled with SQLITE_ENABLE_STAT2 defined, it is created. | |
| 28 ** | |
| 29 ** Argument zWhere may be a pointer to a buffer containing a table name, | |
| 30 ** or it may be a NULL pointer. If it is not NULL, then all entries in | |
| 31 ** the sqlite_stat1 and (if applicable) sqlite_stat2 tables associated | |
| 32 ** with the named table are deleted. If zWhere==0, then code is generated | |
| 33 ** to delete all stat table entries. | |
| 34 */ | |
| 35 static void openStatTable( | |
| 36 Parse *pParse, /* Parsing context */ | |
| 37 int iDb, /* The database we are looking in */ | |
| 38 int iStatCur, /* Open the sqlite_stat1 table on this cursor */ | |
| 39 const char *zWhere /* Delete entries associated with this table */ | |
| 40 ){ | |
| 41 static struct { | |
| 42 const char *zName; | |
| 43 const char *zCols; | |
| 44 } aTable[] = { | |
| 45 { "sqlite_stat1", "tbl,idx,stat" }, | |
| 46 #ifdef SQLITE_ENABLE_STAT2 | |
| 47 { "sqlite_stat2", "tbl,idx,sampleno,sample" }, | |
| 48 #endif | |
| 49 }; | |
| 50 | |
| 51 int aRoot[] = {0, 0}; | |
| 52 u8 aCreateTbl[] = {0, 0}; | |
| 53 | |
| 54 int i; | |
| 55 sqlite3 *db = pParse->db; | |
| 56 Db *pDb; | |
| 57 Vdbe *v = sqlite3GetVdbe(pParse); | |
| 58 if( v==0 ) return; | |
| 59 assert( sqlite3BtreeHoldsAllMutexes(db) ); | |
| 60 assert( sqlite3VdbeDb(v)==db ); | |
| 61 pDb = &db->aDb[iDb]; | |
| 62 | |
| 63 for(i=0; i<ArraySize(aTable); i++){ | |
| 64 const char *zTab = aTable[i].zName; | |
| 65 Table *pStat; | |
| 66 if( (pStat = sqlite3FindTable(db, zTab, pDb->zName))==0 ){ | |
| 67 /* The sqlite_stat[12] table does not exist. Create it. Note that a | |
| 68 ** side-effect of the CREATE TABLE statement is to leave the rootpage | |
| 69 ** of the new table in register pParse->regRoot. This is important | |
| 70 ** because the OpenWrite opcode below will be needing it. */ | |
| 71 sqlite3NestedParse(pParse, | |
| 72 "CREATE TABLE %Q.%s(%s)", pDb->zName, zTab, aTable[i].zCols | |
| 73 ); | |
| 74 aRoot[i] = pParse->regRoot; | |
| 75 aCreateTbl[i] = 1; | |
| 76 }else{ | |
| 77 /* The table already exists. If zWhere is not NULL, delete all entries | |
| 78 ** associated with the table zWhere. If zWhere is NULL, delete the | |
| 79 ** entire contents of the table. */ | |
| 80 aRoot[i] = pStat->tnum; | |
| 81 sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab); | |
| 82 if( zWhere ){ | |
| 83 sqlite3NestedParse(pParse, | |
| 84 "DELETE FROM %Q.%s WHERE tbl=%Q", pDb->zName, zTab, zWhere | |
| 85 ); | |
| 86 }else{ | |
| 87 /* The sqlite_stat[12] table already exists. Delete all rows. */ | |
| 88 sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb); | |
| 89 } | |
| 90 } | |
| 91 } | |
| 92 | |
| 93 /* Open the sqlite_stat[12] tables for writing. */ | |
| 94 for(i=0; i<ArraySize(aTable); i++){ | |
| 95 sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb); | |
| 96 sqlite3VdbeChangeP4(v, -1, (char *)3, P4_INT32); | |
| 97 sqlite3VdbeChangeP5(v, aCreateTbl[i]); | |
| 98 } | |
| 99 } | |
| 100 | |
| 101 /* | |
| 102 ** Generate code to do an analysis of all indices associated with | |
| 103 ** a single table. | |
| 104 */ | |
| 105 static void analyzeOneTable( | |
| 106 Parse *pParse, /* Parser context */ | |
| 107 Table *pTab, /* Table whose indices are to be analyzed */ | |
| 108 int iStatCur, /* Index of VdbeCursor that writes the sqlite_stat1 table */ | |
| 109 int iMem /* Available memory locations begin here */ | |
| 110 ){ | |
| 111 sqlite3 *db = pParse->db; /* Database handle */ | |
| 112 Index *pIdx; /* An index to being analyzed */ | |
| 113 int iIdxCur; /* Cursor open on index being analyzed */ | |
| 114 Vdbe *v; /* The virtual machine being built up */ | |
| 115 int i; /* Loop counter */ | |
| 116 int topOfLoop; /* The top of the loop */ | |
| 117 int endOfLoop; /* The end of the loop */ | |
| 118 int addr; /* The address of an instruction */ | |
| 119 int iDb; /* Index of database containing pTab */ | |
| 120 int regTabname = iMem++; /* Register containing table name */ | |
| 121 int regIdxname = iMem++; /* Register containing index name */ | |
| 122 int regSampleno = iMem++; /* Register containing next sample number */ | |
| 123 int regCol = iMem++; /* Content of a column analyzed table */ | |
| 124 int regRec = iMem++; /* Register holding completed record */ | |
| 125 int regTemp = iMem++; /* Temporary use register */ | |
| 126 int regRowid = iMem++; /* Rowid for the inserted record */ | |
| 127 | |
| 128 #ifdef SQLITE_ENABLE_STAT2 | |
| 129 int regTemp2 = iMem++; /* Temporary use register */ | |
| 130 int regSamplerecno = iMem++; /* Index of next sample to record */ | |
| 131 int regRecno = iMem++; /* Current sample index */ | |
| 132 int regLast = iMem++; /* Index of last sample to record */ | |
| 133 int regFirst = iMem++; /* Index of first sample to record */ | |
| 134 #endif | |
| 135 | |
| 136 v = sqlite3GetVdbe(pParse); | |
| 137 if( v==0 || NEVER(pTab==0) || pTab->pIndex==0 ){ | |
| 138 /* Do no analysis for tables that have no indices */ | |
| 139 return; | |
| 140 } | |
| 141 assert( sqlite3BtreeHoldsAllMutexes(db) ); | |
| 142 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); | |
| 143 assert( iDb>=0 ); | |
| 144 #ifndef SQLITE_OMIT_AUTHORIZATION | |
| 145 if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0, | |
| 146 db->aDb[iDb].zName ) ){ | |
| 147 return; | |
| 148 } | |
| 149 #endif | |
| 150 | |
| 151 /* Establish a read-lock on the table at the shared-cache level. */ | |
| 152 sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); | |
| 153 | |
| 154 iIdxCur = pParse->nTab++; | |
| 155 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ | |
| 156 int nCol = pIdx->nColumn; | |
| 157 KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx); | |
| 158 | |
| 159 if( iMem+1+(nCol*2)>pParse->nMem ){ | |
| 160 pParse->nMem = iMem+1+(nCol*2); | |
| 161 } | |
| 162 | |
| 163 /* Open a cursor to the index to be analyzed. */ | |
| 164 assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) ); | |
| 165 sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb, | |
| 166 (char *)pKey, P4_KEYINFO_HANDOFF); | |
| 167 VdbeComment((v, "%s", pIdx->zName)); | |
| 168 | |
| 169 /* Populate the registers containing the table and index names. */ | |
| 170 if( pTab->pIndex==pIdx ){ | |
| 171 sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0); | |
| 172 } | |
| 173 sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0); | |
| 174 | |
| 175 #ifdef SQLITE_ENABLE_STAT2 | |
| 176 | |
| 177 /* If this iteration of the loop is generating code to analyze the | |
| 178 ** first index in the pTab->pIndex list, then register regLast has | |
| 179 ** not been populated. In this case populate it now. */ | |
| 180 if( pTab->pIndex==pIdx ){ | |
| 181 sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regSamplerecno); | |
| 182 sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES*2-1, regTemp); | |
| 183 sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES*2, regTemp2); | |
| 184 | |
| 185 sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regLast); | |
| 186 sqlite3VdbeAddOp2(v, OP_Null, 0, regFirst); | |
| 187 addr = sqlite3VdbeAddOp3(v, OP_Lt, regSamplerecno, 0, regLast); | |
| 188 sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regLast, regFirst); | |
| 189 sqlite3VdbeAddOp3(v, OP_Multiply, regLast, regTemp, regLast); | |
| 190 sqlite3VdbeAddOp2(v, OP_AddImm, regLast, SQLITE_INDEX_SAMPLES*2-2); | |
| 191 sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regLast, regLast); | |
| 192 sqlite3VdbeJumpHere(v, addr); | |
| 193 } | |
| 194 | |
| 195 /* Zero the regSampleno and regRecno registers. */ | |
| 196 sqlite3VdbeAddOp2(v, OP_Integer, 0, regSampleno); | |
| 197 sqlite3VdbeAddOp2(v, OP_Integer, 0, regRecno); | |
| 198 sqlite3VdbeAddOp2(v, OP_Copy, regFirst, regSamplerecno); | |
| 199 #endif | |
| 200 | |
| 201 /* The block of memory cells initialized here is used as follows. | |
| 202 ** | |
| 203 ** iMem: | |
| 204 ** The total number of rows in the table. | |
| 205 ** | |
| 206 ** iMem+1 .. iMem+nCol: | |
| 207 ** Number of distinct entries in index considering the | |
| 208 ** left-most N columns only, where N is between 1 and nCol, | |
| 209 ** inclusive. | |
| 210 ** | |
| 211 ** iMem+nCol+1 .. Mem+2*nCol: | |
| 212 ** Previous value of indexed columns, from left to right. | |
| 213 ** | |
| 214 ** Cells iMem through iMem+nCol are initialized to 0. The others are | |
| 215 ** initialized to contain an SQL NULL. | |
| 216 */ | |
| 217 for(i=0; i<=nCol; i++){ | |
| 218 sqlite3VdbeAddOp2(v, OP_Integer, 0, iMem+i); | |
| 219 } | |
| 220 for(i=0; i<nCol; i++){ | |
| 221 sqlite3VdbeAddOp2(v, OP_Null, 0, iMem+nCol+i+1); | |
| 222 } | |
| 223 | |
| 224 /* Start the analysis loop. This loop runs through all the entries in | |
| 225 ** the index b-tree. */ | |
| 226 endOfLoop = sqlite3VdbeMakeLabel(v); | |
| 227 sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop); | |
| 228 topOfLoop = sqlite3VdbeCurrentAddr(v); | |
| 229 sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1); | |
| 230 | |
| 231 for(i=0; i<nCol; i++){ | |
| 232 sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol); | |
| 233 #ifdef SQLITE_ENABLE_STAT2 | |
| 234 if( i==0 ){ | |
| 235 /* Check if the record that cursor iIdxCur points to contains a | |
| 236 ** value that should be stored in the sqlite_stat2 table. If so, | |
| 237 ** store it. */ | |
| 238 int ne = sqlite3VdbeAddOp3(v, OP_Ne, regRecno, 0, regSamplerecno); | |
| 239 assert( regTabname+1==regIdxname | |
| 240 && regTabname+2==regSampleno | |
| 241 && regTabname+3==regCol | |
| 242 ); | |
| 243 sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL); | |
| 244 sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 4, regRec, "aaab", 0); | |
| 245 sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regRowid); | |
| 246 sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regRowid); | |
| 247 | |
| 248 /* Calculate new values for regSamplerecno and regSampleno. | |
| 249 ** | |
| 250 ** sampleno = sampleno + 1 | |
| 251 ** samplerecno = samplerecno+(remaining records)/(remaining samples) | |
| 252 */ | |
| 253 sqlite3VdbeAddOp2(v, OP_AddImm, regSampleno, 1); | |
| 254 sqlite3VdbeAddOp3(v, OP_Subtract, regRecno, regLast, regTemp); | |
| 255 sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1); | |
| 256 sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regTemp2); | |
| 257 sqlite3VdbeAddOp3(v, OP_Subtract, regSampleno, regTemp2, regTemp2); | |
| 258 sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regTemp, regTemp); | |
| 259 sqlite3VdbeAddOp3(v, OP_Add, regSamplerecno, regTemp, regSamplerecno); | |
| 260 | |
| 261 sqlite3VdbeJumpHere(v, ne); | |
| 262 sqlite3VdbeAddOp2(v, OP_AddImm, regRecno, 1); | |
| 263 } | |
| 264 #endif | |
| 265 | |
| 266 sqlite3VdbeAddOp3(v, OP_Ne, regCol, 0, iMem+nCol+i+1); | |
| 267 /**** TODO: add collating sequence *****/ | |
| 268 sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL); | |
| 269 } | |
| 270 if( db->mallocFailed ){ | |
| 271 /* If a malloc failure has occurred, then the result of the expression | |
| 272 ** passed as the second argument to the call to sqlite3VdbeJumpHere() | |
| 273 ** below may be negative. Which causes an assert() to fail (or an | |
| 274 ** out-of-bounds write if SQLITE_DEBUG is not defined). */ | |
| 275 return; | |
| 276 } | |
| 277 sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop); | |
| 278 for(i=0; i<nCol; i++){ | |
| 279 sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-(nCol*2)); | |
| 280 sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1); | |
| 281 sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1); | |
| 282 } | |
| 283 | |
| 284 /* End of the analysis loop. */ | |
| 285 sqlite3VdbeResolveLabel(v, endOfLoop); | |
| 286 sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop); | |
| 287 sqlite3VdbeAddOp1(v, OP_Close, iIdxCur); | |
| 288 | |
| 289 /* Store the results in sqlite_stat1. | |
| 290 ** | |
| 291 ** The result is a single row of the sqlite_stat1 table. The first | |
| 292 ** two columns are the names of the table and index. The third column | |
| 293 ** is a string composed of a list of integer statistics about the | |
| 294 ** index. The first integer in the list is the total number of entries | |
| 295 ** in the index. There is one additional integer in the list for each | |
| 296 ** column of the table. This additional integer is a guess of how many | |
| 297 ** rows of the table the index will select. If D is the count of distinct | |
| 298 ** values and K is the total number of rows, then the integer is computed | |
| 299 ** as: | |
| 300 ** | |
| 301 ** I = (K+D-1)/D | |
| 302 ** | |
| 303 ** If K==0 then no entry is made into the sqlite_stat1 table. | |
| 304 ** If K>0 then it is always the case the D>0 so division by zero | |
| 305 ** is never possible. | |
| 306 */ | |
| 307 addr = sqlite3VdbeAddOp1(v, OP_IfNot, iMem); | |
| 308 sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regSampleno); | |
| 309 for(i=0; i<nCol; i++){ | |
| 310 sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0); | |
| 311 sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno); | |
| 312 sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp); | |
| 313 sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1); | |
| 314 sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp); | |
| 315 sqlite3VdbeAddOp1(v, OP_ToInt, regTemp); | |
| 316 sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno); | |
| 317 } | |
| 318 sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0); | |
| 319 sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid); | |
| 320 sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid); | |
| 321 sqlite3VdbeChangeP5(v, OPFLAG_APPEND); | |
| 322 sqlite3VdbeJumpHere(v, addr); | |
| 323 } | |
| 324 } | |
| 325 | |
| 326 /* | |
| 327 ** Generate code that will cause the most recent index analysis to | |
| 328 ** be laoded into internal hash tables where is can be used. | |
| 329 */ | |
| 330 static void loadAnalysis(Parse *pParse, int iDb){ | |
| 331 Vdbe *v = sqlite3GetVdbe(pParse); | |
| 332 if( v ){ | |
| 333 sqlite3VdbeAddOp1(v, OP_LoadAnalysis, iDb); | |
| 334 } | |
| 335 } | |
| 336 | |
| 337 /* | |
| 338 ** Generate code that will do an analysis of an entire database | |
| 339 */ | |
| 340 static void analyzeDatabase(Parse *pParse, int iDb){ | |
| 341 sqlite3 *db = pParse->db; | |
| 342 Schema *pSchema = db->aDb[iDb].pSchema; /* Schema of database iDb */ | |
| 343 HashElem *k; | |
| 344 int iStatCur; | |
| 345 int iMem; | |
| 346 | |
| 347 sqlite3BeginWriteOperation(pParse, 0, iDb); | |
| 348 iStatCur = pParse->nTab; | |
| 349 pParse->nTab += 2; | |
| 350 openStatTable(pParse, iDb, iStatCur, 0); | |
| 351 iMem = pParse->nMem+1; | |
| 352 for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){ | |
| 353 Table *pTab = (Table*)sqliteHashData(k); | |
| 354 analyzeOneTable(pParse, pTab, iStatCur, iMem); | |
| 355 } | |
| 356 loadAnalysis(pParse, iDb); | |
| 357 } | |
| 358 | |
| 359 /* | |
| 360 ** Generate code that will do an analysis of a single table in | |
| 361 ** a database. | |
| 362 */ | |
| 363 static void analyzeTable(Parse *pParse, Table *pTab){ | |
| 364 int iDb; | |
| 365 int iStatCur; | |
| 366 | |
| 367 assert( pTab!=0 ); | |
| 368 assert( sqlite3BtreeHoldsAllMutexes(pParse->db) ); | |
| 369 iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); | |
| 370 sqlite3BeginWriteOperation(pParse, 0, iDb); | |
| 371 iStatCur = pParse->nTab; | |
| 372 pParse->nTab += 2; | |
| 373 openStatTable(pParse, iDb, iStatCur, pTab->zName); | |
| 374 analyzeOneTable(pParse, pTab, iStatCur, pParse->nMem+1); | |
| 375 loadAnalysis(pParse, iDb); | |
| 376 } | |
| 377 | |
| 378 /* | |
| 379 ** Generate code for the ANALYZE command. The parser calls this routine | |
| 380 ** when it recognizes an ANALYZE command. | |
| 381 ** | |
| 382 ** ANALYZE -- 1 | |
| 383 ** ANALYZE <database> -- 2 | |
| 384 ** ANALYZE ?<database>.?<tablename> -- 3 | |
| 385 ** | |
| 386 ** Form 1 causes all indices in all attached databases to be analyzed. | |
| 387 ** Form 2 analyzes all indices the single database named. | |
| 388 ** Form 3 analyzes all indices associated with the named table. | |
| 389 */ | |
| 390 void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){ | |
| 391 sqlite3 *db = pParse->db; | |
| 392 int iDb; | |
| 393 int i; | |
| 394 char *z, *zDb; | |
| 395 Table *pTab; | |
| 396 Token *pTableName; | |
| 397 | |
| 398 /* Read the database schema. If an error occurs, leave an error message | |
| 399 ** and code in pParse and return NULL. */ | |
| 400 assert( sqlite3BtreeHoldsAllMutexes(pParse->db) ); | |
| 401 if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){ | |
| 402 return; | |
| 403 } | |
| 404 | |
| 405 assert( pName2!=0 || pName1==0 ); | |
| 406 if( pName1==0 ){ | |
| 407 /* Form 1: Analyze everything */ | |
| 408 for(i=0; i<db->nDb; i++){ | |
| 409 if( i==1 ) continue; /* Do not analyze the TEMP database */ | |
| 410 analyzeDatabase(pParse, i); | |
| 411 } | |
| 412 }else if( pName2->n==0 ){ | |
| 413 /* Form 2: Analyze the database or table named */ | |
| 414 iDb = sqlite3FindDb(db, pName1); | |
| 415 if( iDb>=0 ){ | |
| 416 analyzeDatabase(pParse, iDb); | |
| 417 }else{ | |
| 418 z = sqlite3NameFromToken(db, pName1); | |
| 419 if( z ){ | |
| 420 pTab = sqlite3LocateTable(pParse, 0, z, 0); | |
| 421 sqlite3DbFree(db, z); | |
| 422 if( pTab ){ | |
| 423 analyzeTable(pParse, pTab); | |
| 424 } | |
| 425 } | |
| 426 } | |
| 427 }else{ | |
| 428 /* Form 3: Analyze the fully qualified table name */ | |
| 429 iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pTableName); | |
| 430 if( iDb>=0 ){ | |
| 431 zDb = db->aDb[iDb].zName; | |
| 432 z = sqlite3NameFromToken(db, pTableName); | |
| 433 if( z ){ | |
| 434 pTab = sqlite3LocateTable(pParse, 0, z, zDb); | |
| 435 sqlite3DbFree(db, z); | |
| 436 if( pTab ){ | |
| 437 analyzeTable(pParse, pTab); | |
| 438 } | |
| 439 } | |
| 440 } | |
| 441 } | |
| 442 } | |
| 443 | |
| 444 /* | |
| 445 ** Used to pass information from the analyzer reader through to the | |
| 446 ** callback routine. | |
| 447 */ | |
| 448 typedef struct analysisInfo analysisInfo; | |
| 449 struct analysisInfo { | |
| 450 sqlite3 *db; | |
| 451 const char *zDatabase; | |
| 452 }; | |
| 453 | |
| 454 /* | |
| 455 ** This callback is invoked once for each index when reading the | |
| 456 ** sqlite_stat1 table. | |
| 457 ** | |
| 458 ** argv[0] = name of the index | |
| 459 ** argv[1] = results of analysis - on integer for each column | |
| 460 */ | |
| 461 static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){ | |
| 462 analysisInfo *pInfo = (analysisInfo*)pData; | |
| 463 Index *pIndex; | |
| 464 int i, c; | |
| 465 unsigned int v; | |
| 466 const char *z; | |
| 467 | |
| 468 assert( argc==2 ); | |
| 469 UNUSED_PARAMETER2(NotUsed, argc); | |
| 470 | |
| 471 if( argv==0 || argv[0]==0 || argv[1]==0 ){ | |
| 472 return 0; | |
| 473 } | |
| 474 pIndex = sqlite3FindIndex(pInfo->db, argv[0], pInfo->zDatabase); | |
| 475 if( pIndex==0 ){ | |
| 476 return 0; | |
| 477 } | |
| 478 z = argv[1]; | |
| 479 for(i=0; *z && i<=pIndex->nColumn; i++){ | |
| 480 v = 0; | |
| 481 while( (c=z[0])>='0' && c<='9' ){ | |
| 482 v = v*10 + c - '0'; | |
| 483 z++; | |
| 484 } | |
| 485 pIndex->aiRowEst[i] = v; | |
| 486 if( *z==' ' ) z++; | |
| 487 } | |
| 488 return 0; | |
| 489 } | |
| 490 | |
| 491 /* | |
| 492 ** If the Index.aSample variable is not NULL, delete the aSample[] array | |
| 493 ** and its contents. | |
| 494 */ | |
| 495 void sqlite3DeleteIndexSamples(Index *pIdx){ | |
| 496 #ifdef SQLITE_ENABLE_STAT2 | |
| 497 if( pIdx->aSample ){ | |
| 498 int j; | |
| 499 sqlite3 *dbMem = pIdx->pTable->dbMem; | |
| 500 for(j=0; j<SQLITE_INDEX_SAMPLES; j++){ | |
| 501 IndexSample *p = &pIdx->aSample[j]; | |
| 502 if( p->eType==SQLITE_TEXT || p->eType==SQLITE_BLOB ){ | |
| 503 sqlite3DbFree(pIdx->pTable->dbMem, p->u.z); | |
| 504 } | |
| 505 } | |
| 506 sqlite3DbFree(dbMem, pIdx->aSample); | |
| 507 pIdx->aSample = 0; | |
| 508 } | |
| 509 #else | |
| 510 UNUSED_PARAMETER(pIdx); | |
| 511 #endif | |
| 512 } | |
| 513 | |
| 514 /* | |
| 515 ** Load the content of the sqlite_stat1 and sqlite_stat2 tables. The | |
| 516 ** contents of sqlite_stat1 are used to populate the Index.aiRowEst[] | |
| 517 ** arrays. The contents of sqlite_stat2 are used to populate the | |
| 518 ** Index.aSample[] arrays. | |
| 519 ** | |
| 520 ** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR | |
| 521 ** is returned. In this case, even if SQLITE_ENABLE_STAT2 was defined | |
| 522 ** during compilation and the sqlite_stat2 table is present, no data is | |
| 523 ** read from it. | |
| 524 ** | |
| 525 ** If SQLITE_ENABLE_STAT2 was defined during compilation and the | |
| 526 ** sqlite_stat2 table is not present in the database, SQLITE_ERROR is | |
| 527 ** returned. However, in this case, data is read from the sqlite_stat1 | |
| 528 ** table (if it is present) before returning. | |
| 529 ** | |
| 530 ** If an OOM error occurs, this function always sets db->mallocFailed. | |
| 531 ** This means if the caller does not care about other errors, the return | |
| 532 ** code may be ignored. | |
| 533 */ | |
| 534 int sqlite3AnalysisLoad(sqlite3 *db, int iDb){ | |
| 535 analysisInfo sInfo; | |
| 536 HashElem *i; | |
| 537 char *zSql; | |
| 538 int rc; | |
| 539 | |
| 540 assert( iDb>=0 && iDb<db->nDb ); | |
| 541 assert( db->aDb[iDb].pBt!=0 ); | |
| 542 assert( sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) ); | |
| 543 | |
| 544 /* Clear any prior statistics */ | |
| 545 for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){ | |
| 546 Index *pIdx = sqliteHashData(i); | |
| 547 sqlite3DefaultRowEst(pIdx); | |
| 548 sqlite3DeleteIndexSamples(pIdx); | |
| 549 } | |
| 550 | |
| 551 /* Check to make sure the sqlite_stat1 table exists */ | |
| 552 sInfo.db = db; | |
| 553 sInfo.zDatabase = db->aDb[iDb].zName; | |
| 554 if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)==0 ){ | |
| 555 return SQLITE_ERROR; | |
| 556 } | |
| 557 | |
| 558 /* Load new statistics out of the sqlite_stat1 table */ | |
| 559 zSql = sqlite3MPrintf(db, | |
| 560 "SELECT idx, stat FROM %Q.sqlite_stat1", sInfo.zDatabase); | |
| 561 if( zSql==0 ){ | |
| 562 rc = SQLITE_NOMEM; | |
| 563 }else{ | |
| 564 (void)sqlite3SafetyOff(db); | |
| 565 rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0); | |
| 566 (void)sqlite3SafetyOn(db); | |
| 567 sqlite3DbFree(db, zSql); | |
| 568 } | |
| 569 | |
| 570 | |
| 571 /* Load the statistics from the sqlite_stat2 table. */ | |
| 572 #ifdef SQLITE_ENABLE_STAT2 | |
| 573 if( rc==SQLITE_OK && !sqlite3FindTable(db, "sqlite_stat2", sInfo.zDatabase) ){ | |
| 574 rc = SQLITE_ERROR; | |
| 575 } | |
| 576 if( rc==SQLITE_OK ){ | |
| 577 sqlite3_stmt *pStmt = 0; | |
| 578 | |
| 579 zSql = sqlite3MPrintf(db, | |
| 580 "SELECT idx,sampleno,sample FROM %Q.sqlite_stat2", sInfo.zDatabase); | |
| 581 if( !zSql ){ | |
| 582 rc = SQLITE_NOMEM; | |
| 583 }else{ | |
| 584 (void)sqlite3SafetyOff(db); | |
| 585 rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0); | |
| 586 (void)sqlite3SafetyOn(db); | |
| 587 sqlite3DbFree(db, zSql); | |
| 588 } | |
| 589 | |
| 590 if( rc==SQLITE_OK ){ | |
| 591 (void)sqlite3SafetyOff(db); | |
| 592 while( sqlite3_step(pStmt)==SQLITE_ROW ){ | |
| 593 char *zIndex = (char *)sqlite3_column_text(pStmt, 0); | |
| 594 Index *pIdx = sqlite3FindIndex(db, zIndex, sInfo.zDatabase); | |
| 595 if( pIdx ){ | |
| 596 int iSample = sqlite3_column_int(pStmt, 1); | |
| 597 sqlite3 *dbMem = pIdx->pTable->dbMem; | |
| 598 assert( dbMem==db || dbMem==0 ); | |
| 599 if( iSample<SQLITE_INDEX_SAMPLES && iSample>=0 ){ | |
| 600 int eType = sqlite3_column_type(pStmt, 2); | |
| 601 | |
| 602 if( pIdx->aSample==0 ){ | |
| 603 static const int sz = sizeof(IndexSample)*SQLITE_INDEX_SAMPLES; | |
| 604 pIdx->aSample = (IndexSample *)sqlite3DbMallocZero(dbMem, sz); | |
| 605 if( pIdx->aSample==0 ){ | |
| 606 db->mallocFailed = 1; | |
| 607 break; | |
| 608 } | |
| 609 } | |
| 610 | |
| 611 assert( pIdx->aSample ); | |
| 612 { | |
| 613 IndexSample *pSample = &pIdx->aSample[iSample]; | |
| 614 pSample->eType = (u8)eType; | |
| 615 if( eType==SQLITE_INTEGER || eType==SQLITE_FLOAT ){ | |
| 616 pSample->u.r = sqlite3_column_double(pStmt, 2); | |
| 617 }else if( eType==SQLITE_TEXT || eType==SQLITE_BLOB ){ | |
| 618 const char *z = (const char *)( | |
| 619 (eType==SQLITE_BLOB) ? | |
| 620 sqlite3_column_blob(pStmt, 2): | |
| 621 sqlite3_column_text(pStmt, 2) | |
| 622 ); | |
| 623 int n = sqlite3_column_bytes(pStmt, 2); | |
| 624 if( n>24 ){ | |
| 625 n = 24; | |
| 626 } | |
| 627 pSample->nByte = (u8)n; | |
| 628 pSample->u.z = sqlite3DbMallocRaw(dbMem, n); | |
| 629 if( pSample->u.z ){ | |
| 630 memcpy(pSample->u.z, z, n); | |
| 631 }else{ | |
| 632 db->mallocFailed = 1; | |
| 633 break; | |
| 634 } | |
| 635 } | |
| 636 } | |
| 637 } | |
| 638 } | |
| 639 } | |
| 640 rc = sqlite3_finalize(pStmt); | |
| 641 (void)sqlite3SafetyOn(db); | |
| 642 } | |
| 643 } | |
| 644 #endif | |
| 645 | |
| 646 if( rc==SQLITE_NOMEM ){ | |
| 647 db->mallocFailed = 1; | |
| 648 } | |
| 649 return rc; | |
| 650 } | |
| 651 | |
| 652 | |
| 653 #endif /* SQLITE_OMIT_ANALYZE */ | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 3108030:
Move bundled copy of sqlite one level deeper to better separate it... (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/src/