database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-08 14:02:16 +03:00
Code Activity

Enhance the ANALYZE command so that it gathers statistics in the sqlite_stat1

Browse Source 
table even for tables that are empty or have no indices.

FossilOrigin-Name: a7645d293801da64a7579737d0a8b48117af2e2c
This commit is contained in:
drh
2010-09-25 22:32:56 +00:00
parent 42825cd215
commit 155640552b
11 changed files with 114 additions and 67 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
src/analyze.c
View File

@@ -114,6 +114,7 @@ static void analyzeOneTable(
int topOfLoop; /* The top of the loop */
int endOfLoop; /* The end of the loop */
int addr; /* The address of an instruction */
int jZeroRows = 0; /* Jump from here if number of rows is zero */
int iDb; /* Index of database containing pTab */
int regTabname = iMem++; /* Register containing table name */
int regIdxname = iMem++; /* Register containing index name */
@@ -132,8 +133,15 @@ static void analyzeOneTable(
#endif
v = sqlite3GetVdbe(pParse);
if( v==0 || NEVER(pTab==0) || pTab->pIndex==0 ){
/* Do no analysis for tables that have no indices */
if( v==0 || NEVER(pTab==0) ){
return;
}
if( pTab->pSelect ){
/* Do not gather statistics on views */
return;
}
if( memcmp(pTab->zName, "sqlite_", 7)==0 ){
/* Do not gather statistics on system tables */
return;
}
assert( sqlite3BtreeHoldsAllMutexes(db) );
@@ -150,6 +158,7 @@ static void analyzeOneTable(
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
iIdxCur = pParse->nTab++;
sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int nCol = pIdx->nColumn;
KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
@@ -164,10 +173,7 @@ static void analyzeOneTable(
(char *)pKey, P4_KEYINFO_HANDOFF);
VdbeComment((v, "%s", pIdx->zName));
/* Populate the registers containing the table and index names. */
if( pTab->pIndex==pIdx ){
sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0);
}
/* Populate the register containing the index name. */
sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0);
#ifdef SQLITE_ENABLE_STAT2
@@ -302,8 +308,10 @@ static void analyzeOneTable(
** If K>0 then it is always the case the D>0 so division by zero
** is never possible.
*/
addr = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regSampleno);
if( jZeroRows==0 ){
jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
}
for(i=0; i<nCol; i++){
sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0);
sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno);
@@ -317,13 +325,35 @@ static void analyzeOneTable(
sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
}
/* If the table has no indices, create a single sqlite_stat1 entry
** containing NULL as the index name and the row count as the content.
*/
if( pTab->pIndex==0 ){
sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb);
VdbeComment((v, "%s", pTab->zName));
sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regSampleno);
sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
}else{
assert( jZeroRows>0 );
addr = sqlite3VdbeAddOp0(v, OP_Goto);
sqlite3VdbeJumpHere(v, jZeroRows);
}
sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid);
sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
if( pParse->nMem<regRec ) pParse->nMem = regRec;
if( jZeroRows ){
sqlite3VdbeJumpHere(v, addr);
}
}
/*
** Generate code that will cause the most recent index analysis to
** be laoded into internal hash tables where is can be used.
** be loaded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){
Vdbe *v = sqlite3GetVdbe(pParse);
@@ -453,33 +483,46 @@ struct analysisInfo {
** This callback is invoked once for each index when reading the
** sqlite_stat1 table.
**
** argv[0] = name of the index
** argv[1] = results of analysis - on integer for each column
** argv[0] = name of the table
** argv[1] = name of the index (might be NULL)
** argv[2] = results of analysis - on integer for each column
**
** Entries for which argv[1]==NULL simply record the number of rows in
** the table.
*/
static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
analysisInfo *pInfo = (analysisInfo*)pData;
Index *pIndex;
int i, c;
Table *pTable;
int i, c, n;
unsigned int v;
const char *z;
assert( argc==2 );
assert( argc==3 );
UNUSED_PARAMETER2(NotUsed, argc);
if( argv==0 || argv[0]==0 || argv[1]==0 ){
if( argv==0 || argv[0]==0 || argv[2]==0 ){
return 0;
}
pIndex = sqlite3FindIndex(pInfo->db, argv[0], pInfo->zDatabase);
if( pIndex==0 ){
pTable = sqlite3FindTable(pInfo->db, argv[0], pInfo->zDatabase);
if( pTable==0 ){
return 0;
}
z = argv[1];
for(i=0; *z && i<=pIndex->nColumn; i++){
if( argv[1] ){
pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase);
}else{
pIndex = 0;
}
n = pIndex ? pIndex->nColumn : 0;
z = argv[2];
for(i=0; *z && i<=n; i++){
v = 0;
while( (c=z[0])>='0' && c<='9' ){
v = v*10 + c - '0';
z++;
}
if( i==0 ) pTable->nRowEst = v;
if( pIndex==0 ) break;
pIndex->aiRowEst[i] = v;
if( *z==' ' ) z++;
}
@@ -555,7 +598,7 @@ int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
/* Load new statistics out of the sqlite_stat1 table */
zSql = sqlite3MPrintf(db,
"SELECT idx, stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
"SELECT tbl, idx, stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
if( zSql==0 ){
rc = SQLITE_NOMEM;
}else{