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Overview
| Comment: | The pragma as eponymous virtual table mechanism now appears to work. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | pragma-as-vtab |
| Files: | files | file ages | folders |
| SHA1: |
2c274a1a7b57ef1208901fbc1d96d39c |
| User & Date: | drh 2016-12-15 21:11:15.541 |
Context
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2016-12-15
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| 21:33 | Fix the cost estimation in the BestIndex method of the eponymous pragma virtual table implementation. (check-in: 7126807a18 user: drh tags: pragma-as-vtab) | |
| 21:11 | The pragma as eponymous virtual table mechanism now appears to work. (check-in: 2c274a1a7b user: drh tags: pragma-as-vtab) | |
| 20:59 | Code to automatically create eponymous virtual tables for read-only pragmas. Compiles, but does not yet work. (check-in: 988a61e8b0 user: drh tags: pragma-as-vtab) | |
Changes
Changes to src/pragma.c.
| ︙ | ︙ | |||
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char cSep = '(';
StrAccum acc;
char zBuf[200];
sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
sqlite3StrAccumAppendAll(&acc, "CREATE TABLE x");
for(i=0, j=pPragma->iPragCName; i<pPragma->nPragCName; i++, j++){
| < | | 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 |
char cSep = '(';
StrAccum acc;
char zBuf[200];
sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
sqlite3StrAccumAppendAll(&acc, "CREATE TABLE x");
for(i=0, j=pPragma->iPragCName; i<pPragma->nPragCName; i++, j++){
sqlite3XPrintf(&acc, "%c\"%s\"", cSep, pragCName[j]);
cSep = ',';
}
j = 0;
if( pPragma->mPragFlg & PragFlg_Result1 ){
sqlite3StrAccumAppendAll(&acc, ",arg HIDDEN");
j++;
}
|
| ︙ | ︙ | |||
2064 2065 2066 2067 2068 2069 2070 |
for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
if( pConstraint->usable==0 ) continue;
if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
if( pConstraint->iColumn < pTab->iHidden ) continue;
j = pConstraint->iColumn - pTab->iHidden;
assert( j < 2 );
if( seen[j] ) continue;
| | | | | 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 |
for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
if( pConstraint->usable==0 ) continue;
if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
if( pConstraint->iColumn < pTab->iHidden ) continue;
j = pConstraint->iColumn - pTab->iHidden;
assert( j < 2 );
if( seen[j] ) continue;
seen[j] = i+1;
}
if( seen[0]==0 ){
pIdxInfo->estimatedCost = (double)2147483647;
pIdxInfo->estimatedRows = 2147483647;
return SQLITE_OK;
}
j = seen[0]-1;
pIdxInfo->aConstraintUsage[j].argvIndex = 1;
pIdxInfo->aConstraintUsage[j].omit = 1;
if( seen[1]==0 ) return SQLITE_OK;
pIdxInfo->estimatedCost = (double)20;
pIdxInfo->estimatedRows = 20;
j = seen[1]-1;
pIdxInfo->aConstraintUsage[j].argvIndex = 2;
pIdxInfo->aConstraintUsage[j].omit = 1;
return SQLITE_OK;
}
/* Create a new cursor for the pragma virtual table */
static int pragmaVtabOpen(sqlite3_vtab *pVtab, sqlite3_vtab_cursor **ppCursor){
|
| ︙ | ︙ | |||
2152 2153 2154 2155 2156 2157 2158 |
for(i=0; i<argc; i++){
assert( i<ArraySize(pCsr->azArg) );
pCsr->azArg[i] = sqlite3_mprintf("%s", sqlite3_value_text(argv[i]));
if( pCsr->azArg[i]==0 ){
return SQLITE_NOMEM;
}
}
| | | 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 |
for(i=0; i<argc; i++){
assert( i<ArraySize(pCsr->azArg) );
pCsr->azArg[i] = sqlite3_mprintf("%s", sqlite3_value_text(argv[i]));
if( pCsr->azArg[i]==0 ){
return SQLITE_NOMEM;
}
}
sqlite3StrAccumInit(&acc, 0, 0, 0, pTab->db->aLimit[SQLITE_LIMIT_SQL_LENGTH]);
sqlite3StrAccumAppendAll(&acc, "PRAGMA ");
if( pCsr->azArg[1] ){
sqlite3XPrintf(&acc, "%Q.", pCsr->azArg[1]);
}
sqlite3StrAccumAppendAll(&acc, pTab->pName->zName);
if( pCsr->azArg[0] ){
sqlite3XPrintf(&acc, "=%Q", pCsr->azArg[0]);
|
| ︙ | ︙ | |||
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Module *sqlite3PragmaVtabRegister(sqlite3 *db, const char *zName){
const PragmaName *pName;
assert( sqlite3_strnicmp(zName, "pragma_", 7)==0 );
pName = pragmaLocate(zName+7);
if( pName==0 ) return 0;
if( (pName->mPragFlg & (PragFlg_Result0|PragFlg_Result1))==0 ) return 0;
assert( sqlite3HashFind(&db->aModule, zName)==0 );
| | | 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 |
Module *sqlite3PragmaVtabRegister(sqlite3 *db, const char *zName){
const PragmaName *pName;
assert( sqlite3_strnicmp(zName, "pragma_", 7)==0 );
pName = pragmaLocate(zName+7);
if( pName==0 ) return 0;
if( (pName->mPragFlg & (PragFlg_Result0|PragFlg_Result1))==0 ) return 0;
assert( sqlite3HashFind(&db->aModule, zName)==0 );
return sqlite3VtabCreateModule(db, zName, &pragmaVtabModule, (void*)pName, 0);
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
#endif /* SQLITE_OMIT_PRAGMA */
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