-C Add\sthe\sexperimental\ssqlite3_stmt_explain(S,E)\sinterface.
-D 2023-07-15T16:48:14.281
+C Enhance\sthe\ssqlite3_stmt_explain()\sinterface\sso\sthat\savoids\sunnecessary\nreprepare\soperations.
+D 2023-07-18T17:29:05.187
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
F src/random.c 606b00941a1d7dd09c381d3279a058d771f406c5213c9932bbd93d5587be4b9c
F src/resolve.c 37953a5f36c60bea413c3c04efcd433b6177009f508ef2ace0494728912fe2e9
F src/rowset.c 8432130e6c344b3401a8874c3cb49fefe6873fec593294de077afea2dce5ec97
-F src/select.c 3ab1186290a311a8ceed1286c0e286209f7fe97b2d02c7593258004ce295dd88
+F src/select.c 3328b8c758016b400a4fea053ab1f5927929083a49d0c3921802ce99eea73cde
F src/shell.c.in 3f125426a25c717fbf8b84b3b75a8b60fa989bf7a039ed38926d455329f9dd0f
-F src/sqlite.h.in 13d5458cd23e7b4759cff4d978ad09591a457b4a2821993579953a9a4257ce0f
+F src/sqlite.h.in 7b95e5b11914726ebcf95c633be3341ad2cb3c8aac62ecf188a14f74827aa68a
F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
F src/sqlite3ext.h da473ce2b3d0ae407a6300c4a164589b9a6bfdbec9462688a8593ff16f3bb6e4
F src/sqliteInt.h dcb1a885e8b6cb78df618944b89d44361a99d0fe33e1bba2c150a855f7dc5599
F src/vacuum.c 604fcdaebe76f3497c855afcbf91b8fa5046b32de3045bab89cc008d68e40104
F src/vdbe.c 74282a947234513872a83b0bab1b8c644ece64b3e27b053ef17677c8ff9c81e0
F src/vdbe.h 41485521f68e9437fdb7ec4a90f9d86ab294e9bb8281e33b235915e29122cfc0
-F src/vdbeInt.h 7bd49eef8f89c1a271fbf12d80a206bf56c876814c5fc6bee340f4e1907095ae
-F src/vdbeapi.c c528ef4fafc8be172cbe4f48d8f15c9526bebde9f90185917fcc43fad264bcb6
-F src/vdbeaux.c b5e3f7e158518b4eca6f166ac43900640a3fe9735c710e12bfa119af21059339
+F src/vdbeInt.h 7a2329efe451ef0d1280736419f321cbc261146e453cdd22b27a0785b8742b15
+F src/vdbeapi.c 97a9dfdff49183ad7f7911f9d919eb8eb72677c39cdee6249ee5a060d3ce515a
+F src/vdbeaux.c 499b68a5585663ef36c05b421d8c9c60448aa3b9f01bba5ae7accfc89ee6ac50
F src/vdbeblob.c 2516697b3ee8154eb8915f29466fb5d4f1ae39ee8b755ea909cefaf57ec5e2ce
F src/vdbemem.c cf4a1556dd5b18c071cf7c243373c29ce752eb516022e3ad49ba72f08b785033
F src/vdbesort.c 0d40dca073c94e158ead752ef4225f4fee22dee84145e8c00ca2309afb489015
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 984d491eb3fe06f714bf07d6873321f3992a072812b46508e599bfefd39dff3e
-R d7676f37f2e59b0f85cc021dadb3d7bc
-T *branch * sqlite3_stmt_explain
-T *sym-sqlite3_stmt_explain *
-T -sym-trunk *
+P 5683743ddf0bb051f2fe5d137cc18407e000e77e9faa9010a22e3134b575638b
+R a56fcd1282b166331b87ac37d0175ebe
U drh
-Z bc12630434faa3e2cbe8d73f4285c221
+Z 96b7009f78463b1b25a8594262247cfd
# Remove this line to create a well-formed Fossil manifest.
-5683743ddf0bb051f2fe5d137cc18407e000e77e9faa9010a22e3134b575638b
\ No newline at end of file
+050f773addd605f6690348c98e9000a9a3663bbc26288a71973fd7b40468e8ab
\ No newline at end of file
int fullName; /* TABLE.COLUMN if no AS clause and is a direct table ref */
int srcName; /* COLUMN or TABLE.COLUMN if no AS clause and is direct */
-#ifndef SQLITE_OMIT_EXPLAIN
- /* If this is an EXPLAIN, skip this step */
- if( pParse->explain ){
- return;
- }
-#endif
-
if( pParse->colNamesSet ) return;
/* Column names are determined by the left-most term of a compound select */
while( pSelect->pPrior ) pSelect = pSelect->pPrior;
** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
** METHOD: sqlite3_stmt
**
-** ^The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
+** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
** setting for prepared statement S. If E is zero, then S becomes
** a normal prepared statement. If E is 1, then S behaves as if
** its SQL text began with "EXPLAIN". If E is 2, then S behaves as if
** its SQL text began with "EXPLAIN QUERY PLAN".
**
-** Calling sqlite3_stmt_explain(S,E) causes prepared statement S
-** to be reprepared. A call to sqlite3_stmt_explain(S,E) will fail
-** with SQLITE_ERROR if S cannot be re-prepared because it was created
-** using sqlite3_prepare() instead of the newer sqlite_prepare_v2() or
-** sqlite3_prepare_v3() interfaces and hence has no saved SQL text with
-** which to reprepare. Changing the explain setting for a prepared
-** statement does not change the original SQL text for the statement.
-** Hence, if the SQL text originally began with EXPLAIN or EXPLAIN
-** QUERY PLAN, but sqlite3_stmt_explain(S,0) is called to convert the
-** statement into an ordinary statement, the EXPLAIN or EXPLAIN QUERY
-** PLAN keywords still appear in the sqlite3_sql(S) output, even though
-** the statement now acts like a normal SQL statement.
+** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
+** SQLite tries to avoid a reprepare, but a reprepare might be necessary
+** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
+**
+** Because of the potential need to reprepare, a call to
+** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
+** reprepared because it was created using sqlite3_prepare() instead of
+** the newer sqlite_prepare_v2() or sqlite3_prepare_v3() interfaces and
+** hence has no saved SQL text with which to reprepare.
+**
+** Changing the explain setting for a prepared statement does not change
+** the original SQL text for the statement. Hence, if the SQL text originally
+** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
+** is called to convert the statement into an ordinary statement, the EXPLAIN
+** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
+** output, even though the statement now acts like a normal SQL statement.
**
** This routine returns SQLITE_OK if the explain mode is successfully
** changed, or an error code if the explain mode could not be changed.
u32 nWrite; /* Number of write operations that have occurred */
#endif
u16 nResColumn; /* Number of columns in one row of the result set */
+ u16 nResAlloc; /* Column slots allocated to aColName[] */
u8 errorAction; /* Recovery action to do in case of an error */
u8 minWriteFileFormat; /* Minimum file format for writable database files */
u8 prepFlags; /* SQLITE_PREPARE_* flags */
u8 eVdbeState; /* On of the VDBE_*_STATE values */
bft expired:2; /* 1: recompile VM immediately 2: when convenient */
- bft explain:2; /* True if EXPLAIN present on SQL command */
+ bft explain:2; /* 0: normal, 1: EXPLAIN, 2: EXPLAIN QUERY PLAN */
bft changeCntOn:1; /* True to update the change-counter */
bft usesStmtJournal:1; /* True if uses a statement journal */
bft readOnly:1; /* True for statements that do not write */
bft bIsReader:1; /* True for statements that read */
+ bft haveEqpOps:1; /* Bytecode supports EXPLAIN QUERY PLAN */
yDbMask btreeMask; /* Bitmask of db->aDb[] entries referenced */
yDbMask lockMask; /* Subset of btreeMask that requires a lock */
u32 aCounter[9]; /* Counters used by sqlite3_stmt_status() */
*/
int sqlite3_column_count(sqlite3_stmt *pStmt){
Vdbe *pVm = (Vdbe *)pStmt;
- return pVm ? pVm->nResColumn : 0;
+ if( pVm==0 ) return 0;
+ return pVm->nResColumn;
}
/*
return iType;
}
+/*
+** Column names appropriate for EXPLAIN or EXPLAIN QUERY PLAN.
+*/
+static const char * const azExplainColNames8[] = {
+ "addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment", /* EXPLAIN */
+ "id", "parent", "notused", "detail" /* EQP */
+};
+static const u16 azExplainColNames16data[] = {
+ /* 0 */ 'a', 'd', 'd', 'r', 0,
+ /* 5 */ 'o', 'p', 'c', 'o', 'd', 'e', 0,
+ /* 12 */ 'p', '1', 0,
+ /* 15 */ 'p', '2', 0,
+ /* 18 */ 'p', '3', 0,
+ /* 21 */ 'p', '4', 0,
+ /* 24 */ 'p', '5', 0,
+ /* 27 */ 'c', 'o', 'm', 'm', 'e', 'n', 't', 0,
+ /* 35 */ 'i', 'd', 0,
+ /* 38 */ 'p', 'a', 'r', 'e', 'n', 't', 0,
+ /* 45 */ 'n', 'o', 't', 'u', 's', 'e', 'd', 0,
+ /* 53 */ 'd', 'e', 't', 'a', 'i', 'l', 0
+};
+static const u8 iExplainColNames16[] = {
+ 0, 5, 12, 15, 18, 21, 24, 27,
+ 35, 38, 45, 53
+};
+
/*
** Convert the N-th element of pStmt->pColName[] into a string using
** xFunc() then return that string. If N is out of range, return 0.
return 0;
}
#endif
+ if( N<0 ) return 0;
ret = 0;
p = (Vdbe *)pStmt;
db = p->db;
assert( db!=0 );
- n = sqlite3_column_count(pStmt);
- if( N<n && N>=0 ){
+ sqlite3_mutex_enter(db->mutex);
+
+ if( p->explain ){
+ if( useType>0 ) goto columnName_end;
+ n = p->explain==1 ? 8 : 4;
+ if( N>=n ) goto columnName_end;
+ if( useUtf16 ){
+ int i = iExplainColNames16[N + 8*p->explain - 8];
+ ret = (void*)&azExplainColNames16data[i];
+ }else{
+ ret = (void*)azExplainColNames8[N + 8*p->explain - 8];
+ }
+ goto columnName_end;
+ }
+ n = p->nResColumn;
+ if( N<n ){
u8 prior_mallocFailed = db->mallocFailed;
N += useType*n;
- sqlite3_mutex_enter(db->mutex);
#ifndef SQLITE_OMIT_UTF16
if( useUtf16 ){
ret = sqlite3_value_text16((sqlite3_value*)&p->aColName[N]);
sqlite3OomClear(db);
ret = 0;
}
- sqlite3_mutex_leave(db->mutex);
}
+columnName_end:
+ sqlite3_mutex_leave(db->mutex);
return ret;
}
if( v->explain==eMode ) return SQLITE_OK;
if( v->zSql==0 || eMode<0 || eMode>2 ) return SQLITE_ERROR;
sqlite3_mutex_enter(v->db->mutex);
- v->explain = eMode;
- rc = sqlite3Reprepare(v);
+ if( v->nMem>=10 && (eMode!=2 || v->haveEqpOps) ){
+ /* No reprepare necessary */
+ v->explain = eMode;
+ rc = SQLITE_OK;
+ }else{
+ int haveEqpOps = v->explain==2 || v->haveEqpOps;
+ v->explain = eMode;
+ rc = sqlite3Reprepare(v);
+ v->haveEqpOps = haveEqpOps!=0;
+ }
+ if( v->explain ){
+ v->nResColumn = 12 - 4*v->explain;
+ }else{
+ v->nResColumn = v->nResAlloc;
+ }
sqlite3_mutex_leave(v->db->mutex);
return rc;
}
sqlite3VdbeMemSetInt64(pMem, pOp->p1);
sqlite3VdbeMemSetInt64(pMem+1, pOp->p2);
sqlite3VdbeMemSetInt64(pMem+2, pOp->p3);
- sqlite3VdbeMemSetStr(pMem+3, zP4, -1, SQLITE_UTF8, sqlite3_free);
- p->nResColumn = 4;
+ sqlite3VdbeMemSetStr(pMem+3, zP4, -1, SQLITE_UTF8, sqlite3_free);
+ assert( p->nResColumn==4 );
}else{
sqlite3VdbeMemSetInt64(pMem+0, i);
sqlite3VdbeMemSetStr(pMem+1, (char*)sqlite3OpcodeName(pOp->opcode),
sqlite3VdbeMemSetNull(pMem+7);
#endif
sqlite3VdbeMemSetStr(pMem+5, zP4, -1, SQLITE_UTF8, sqlite3_free);
- p->nResColumn = 8;
+ assert( p->nResColumn==8 );
}
p->pResultRow = pMem;
if( db->mallocFailed ){
resolveP2Values(p, &nArg);
p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
if( pParse->explain ){
- static const char * const azColName[] = {
- "addr", "opcode", "p1", "p2", "p3", "p4", "p5", "comment",
- "id", "parent", "notused", "detail"
- };
- int iFirst, mx, i;
if( nMem<10 ) nMem = 10;
p->explain = pParse->explain;
- if( pParse->explain==2 ){
- sqlite3VdbeSetNumCols(p, 4);
- iFirst = 8;
- mx = 12;
- }else{
- sqlite3VdbeSetNumCols(p, 8);
- iFirst = 0;
- mx = 8;
- }
- for(i=iFirst; i<mx; i++){
- sqlite3VdbeSetColName(p, i-iFirst, COLNAME_NAME,
- azColName[i], SQLITE_STATIC);
- }
+ p->nResColumn = 12 - 4*p->explain;
}
p->expired = 0;
int n;
sqlite3 *db = p->db;
- if( p->nResColumn ){
- releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
+ if( p->nResAlloc ){
+ releaseMemArray(p->aColName, p->nResAlloc*COLNAME_N);
sqlite3DbFree(db, p->aColName);
}
n = nResColumn*COLNAME_N;
- p->nResColumn = (u16)nResColumn;
+ p->nResColumn = p->nResAlloc = (u16)nResColumn;
p->aColName = (Mem*)sqlite3DbMallocRawNN(db, sizeof(Mem)*n );
if( p->aColName==0 ) return;
initMemArray(p->aColName, n, db, MEM_Null);
){
int rc;
Mem *pColName;
- assert( idx<p->nResColumn );
+ assert( idx<p->nResAlloc );
assert( var<COLNAME_N );
if( p->db->mallocFailed ){
assert( !zName || xDel!=SQLITE_DYNAMIC );
return SQLITE_NOMEM_BKPT;
}
assert( p->aColName!=0 );
- pColName = &(p->aColName[idx+var*p->nResColumn]);
+ pColName = &(p->aColName[idx+var*p->nResAlloc]);
rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, xDel);
assert( rc!=0 || !zName || (pColName->flags&MEM_Term)!=0 );
return rc;
assert( db!=0 );
assert( p->db==0 || p->db==db );
if( p->aColName ){
- releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
+ releaseMemArray(p->aColName, p->nResAlloc*COLNAME_N);
sqlite3DbNNFreeNN(db, p->aColName);
}
for(pSub=p->pProgram; pSub; pSub=pNext){
projects / thirdparty / sqlite.git / commitdiff
