/*
** Implementation of the stat_init(N,K,C) SQL function. The three parameters
** are:
-** N: The number of columns in the index including the rowid/pk
-** K: The number of columns in the index excluding the rowid/pk
-** C: The number of rows in the index
+** N: The number of columns in the index including the rowid/pk (note 1)
+** K: The number of columns in the index excluding the rowid/pk.
+** C: The number of rows in the index (note 2)
**
-** C is only used for STAT3 and STAT4.
+** Note 1: In the special case of the covering index that implements a
+** WITHOUT ROWID table, N is the number of PRIMARY KEY columns, not the
+** total number of columns in the table.
**
-** For ordinary rowid tables, N==K+1. But for WITHOUT ROWID tables,
-** N=K+P where P is the number of columns in the primary key. For the
-** covering index that implements the original WITHOUT ROWID table, N==K.
+** Note 2: C is only used for STAT3 and STAT4.
+**
+** For indexes on ordinary rowid tables, N==K+1. But for indexes on
+** WITHOUT ROWID tables, N=K+P where P is the number of columns in the
+** PRIMARY KEY of the table. The covering index that implements the
+** original WITHOUT ROWID table as N==K as a special case.
**
** This routine allocates the Stat4Accum object in heap memory. The return
** value is a pointer to the the Stat4Accum object encoded as a blob (i.e.
** R Rowid for the current row. Might be a key record for
** WITHOUT ROWID tables.
**
-** The SQL function always returns NULL.
+** This SQL function always returns NULL. It's purpose it to accumulate
+** statistical data and/or samples in the Stat4Accum object about the
+** index being analyzed. The stat_get() SQL function will later be used to
+** extract relevant information for constructing the sqlite_statN tables.
**
** The R parameter is only used for STAT3 and STAT4
*/
/*
** Implementation of the stat_get(P,J) SQL function. This routine is
-** used to query the results. Content is returned for parameter J
+** used to query statistical information that has been gathered into
+** the Stat4Accum object by prior calls to stat_push(). The P parameter
+** is a BLOB which is decoded into a pointer to the Stat4Accum objects.
+** The content to returned is determined by the parameter J
** which is one of the STAT_GET_xxxx values defined above.
**
** If neither STAT3 nor STAT4 are enabled, then J is always
sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
- int nCol; /* Number of columns indexed by pIdx */
+ int nCol; /* Number of columns in pIdx. "N" */
int *aGotoChng; /* Array of jump instruction addresses */
int addrRewind; /* Address of "OP_Rewind iIdxCur" */
- int addrGotoChng0; /* Address of "Goto addr_chng_0" */
int addrNextRow; /* Address of "next_row:" */
const char *zIdxName; /* Name of the index */
+ int nColTest; /* Number of columns to test for changes */
if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;
if( pIdx->pPartIdxWhere==0 ) needTableCnt = 0;
if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIdx) ){
nCol = pIdx->nKeyCol;
zIdxName = pTab->zName;
+ nColTest = nCol - 1;
}else{
nCol = pIdx->nColumn;
zIdxName = pIdx->zName;
+ nColTest = pIdx->onError==OE_None ? nCol-1 : pIdx->nKeyCol-1;
}
- aGotoChng = sqlite3DbMallocRaw(db, sizeof(int)*(nCol+1));
+ aGotoChng = sqlite3DbMallocRaw(db, sizeof(int)*(nColTest+1));
if( aGotoChng==0 ) continue;
/* Populate the register containing the index name. */
** the regPrev array and a trailing rowid (the rowid slot is required
** when building a record to insert into the sample column of
** the sqlite_stat4 table. */
- pParse->nMem = MAX(pParse->nMem, regPrev+nCol);
+ pParse->nMem = MAX(pParse->nMem, regPrev+nColTest);
/* Open a read-only cursor on the index being analyzed. */
assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
/* Invoke the stat_init() function. The arguments are:
**
- ** (1) the number of columns in the index including the rowid,
- ** (2) the number of rows in the index,
+ ** (1) the number of columns in the index including the rowid
+ ** (or for a WITHOUT ROWID table, the number of PK columns),
+ ** (2) the number of columns in the key without the rowid/pk
+ ** (3) the number of rows in the index,
+ **
**
- ** The second argument is only used for STAT3 and STAT4
+ ** The third argument is only used for STAT3 and STAT4
*/
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat4+3);
addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
- addrGotoChng0 = sqlite3VdbeAddOp0(v, OP_Goto);
-
- /*
- ** next_row:
- ** regChng = 0
- ** if( idx(0) != regPrev(0) ) goto chng_addr_0
- ** regChng = 1
- ** if( idx(1) != regPrev(1) ) goto chng_addr_1
- ** ...
- ** regChng = N
- ** goto chng_addr_N
- */
addrNextRow = sqlite3VdbeCurrentAddr(v);
- for(i=0; i<nCol-1; i++){
- char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
- sqlite3VdbeAddOp2(v, OP_Integer, i, regChng);
- sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp);
- aGotoChng[i] =
- sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ);
- sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
- VdbeCoverage(v);
- }
- sqlite3VdbeAddOp2(v, OP_Integer, nCol-1, regChng);
- aGotoChng[nCol] = sqlite3VdbeAddOp0(v, OP_Goto);
- /*
- ** chng_addr_0:
- ** regPrev(0) = idx(0)
- ** chng_addr_1:
- ** regPrev(1) = idx(1)
- ** ...
- */
- sqlite3VdbeJumpHere(v, addrGotoChng0);
- for(i=0; i<nCol-1; i++){
- sqlite3VdbeJumpHere(v, aGotoChng[i]);
- sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);
+ if( nColTest>0 ){
+ /*
+ ** next_row:
+ ** regChng = 0
+ ** if( idx(0) != regPrev(0) ) goto chng_addr_0
+ ** regChng = 1
+ ** if( idx(1) != regPrev(1) ) goto chng_addr_1
+ ** ...
+ ** regChng = N
+ ** goto chng_addr_N
+ */
+ sqlite3VdbeAddOp0(v, OP_Goto);
+ addrNextRow = sqlite3VdbeCurrentAddr(v);
+ for(i=0; i<nColTest; i++){
+ char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]);
+ sqlite3VdbeAddOp2(v, OP_Integer, i, regChng);
+ sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp);
+ aGotoChng[i] =
+ sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ);
+ sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
+ VdbeCoverage(v);
+ }
+ sqlite3VdbeAddOp2(v, OP_Integer, nColTest, regChng);
+ aGotoChng[nColTest] = sqlite3VdbeAddOp0(v, OP_Goto);
+
+
+ /*
+ ** chng_addr_0:
+ ** regPrev(0) = idx(0)
+ ** chng_addr_1:
+ ** regPrev(1) = idx(1)
+ ** ...
+ */
+ sqlite3VdbeJumpHere(v, addrNextRow-1);
+ for(i=0; i<nColTest; i++){
+ sqlite3VdbeJumpHere(v, aGotoChng[i]);
+ sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i);
+ }
+ sqlite3VdbeJumpHere(v, aGotoChng[nColTest]);
}
-
+
/*
** chng_addr_N:
** regRowid = idx(rowid) // STAT34 only
** Next csr
** if !eof(csr) goto next_row;
*/
- sqlite3VdbeJumpHere(v, aGotoChng[nCol]);
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
assert( regRowid==(regStat4+2) );
if( HasRowid(pTab) ){
projects / thirdparty / sqlite.git / commitdiff
