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Add the "PRAGMA analyze_as_needed" command.

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FossilOrigin-Name: e93db2373127d31d33ec46ef918fa9386bb664a6
This commit is contained in:
drh
2017-02-17 16:26:34 +00:00
parent a3928dd7be
commit 72052a73a3
8 changed files with 141 additions and 82 deletions
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88
src/analyze.c
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@@ -1286,28 +1286,66 @@ static void loadAnalysis(Parse *pParse, int iDb){
}
/*
** Generate code that will do an analysis of an entire database
** Return true if table pTab is in need of being reanalyzed.
*/
static void analyzeDatabase(Parse *pParse, int iDb){
static int analyzeNeeded(Table *pTab){
Index *pIdx;
if( (pTab->tabFlags & TF_StatsUsed)==0 ) return 0;
if( (pTab->tabFlags & TF_SizeChng)!=0 ) return 1;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( !pIdx->hasStat1 ) return 1;
}
return 0;
}
/*
** Generate code that will do an analysis of an entire database.
**
** Return a count of the number of tables actually analyzed. Return 0
** if nothing was analyzed.
*/
static int analyzeDatabase(Parse *pParse, int iDbReq, int onlyIfNeeded){
sqlite3 *db = pParse->db;
Schema *pSchema = db->aDb[iDb].pSchema; /* Schema of database iDb */
Schema *pSchema;
HashElem *k;
int iStatCur;
int iMem;
int iTab;
int iDb; /* Database currently being analyzed */
int iDbFirst, iDbLast; /* Range of databases to be analyzed */
int cnt; /* Number of tables analyzed in a single database */
int allCnt = 0; /* Number of tables analyzed across all databases */
sqlite3BeginWriteOperation(pParse, 0, iDb);
iStatCur = pParse->nTab;
pParse->nTab += 3;
openStatTable(pParse, iDb, iStatCur, 0, 0);
iMem = pParse->nMem+1;
iTab = pParse->nTab;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
Table *pTab = (Table*)sqliteHashData(k);
analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab);
if( iDbReq>=0 ){
iDbFirst = iDbLast = iDbReq;
}else{
iDbFirst = 0;
iDbLast = db->nDb-1;
}
loadAnalysis(pParse, iDb);
for(iDb=iDbFirst; iDb<=iDbLast; iDb++){
if( iDb==1 ) continue; /* Do not analyze the TEMP database */
pSchema = db->aDb[iDb].pSchema;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
cnt = 0;
for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
Table *pTab = (Table*)sqliteHashData(k);
if( !onlyIfNeeded || analyzeNeeded(pTab) ){
if( cnt==0 ){
sqlite3BeginWriteOperation(pParse, 0, iDb);
iStatCur = pParse->nTab;
pParse->nTab += 3;
openStatTable(pParse, iDb, iStatCur, 0, 0);
iMem = pParse->nMem+1;
iTab = pParse->nTab;
}
analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab);
cnt++;
allCnt++;
}
}
if( cnt ) loadAnalysis(pParse, iDb);
}
return allCnt;
}
/*
@@ -1345,16 +1383,21 @@ static void analyzeTable(Parse *pParse, Table *pTab, Index *pOnlyIdx){
** Form 1 causes all indices in all attached databases to be analyzed.
** Form 2 analyzes all indices the single database named.
** Form 3 analyzes all indices associated with the named table.
**
** If pName1 and pName2 are both NULL and if the ifNeeded flag is true,
** this routine computes an conditional ANALYZE on only those tables
** are believed to be in need of analysis. The conditional analysis
** might well be a no-op.
*/
void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2, int ifNeeded){
sqlite3 *db = pParse->db;
int iDb;
int i;
char *z, *zDb;
Table *pTab;
Index *pIdx;
Token *pTableName;
Vdbe *v;
int needExpire = 1;
/* Read the database schema. If an error occurs, leave an error message
** and code in pParse and return NULL. */
@@ -1366,15 +1409,12 @@ void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
assert( pName2!=0 || pName1==0 );
if( pName1==0 ){
/* Form 1: Analyze everything */
for(i=0; i<db->nDb; i++){
if( i==1 ) continue; /* Do not analyze the TEMP database */
analyzeDatabase(pParse, i);
}
needExpire = analyzeDatabase(pParse, -1, ifNeeded) || ifNeeded==0;
}else if( pName2->n==0 ){
/* Form 2: Analyze the database or table named */
iDb = sqlite3FindDb(db, pName1);
if( iDb>=0 ){
analyzeDatabase(pParse, iDb);
analyzeDatabase(pParse, iDb, 0);
}else{
z = sqlite3NameFromToken(db, pName1);
if( z ){
@@ -1402,8 +1442,10 @@ void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
}
}
}
v = sqlite3GetVdbe(pParse);
if( v ) sqlite3VdbeAddOp0(v, OP_Expire);
if( needExpire ){
v = sqlite3GetVdbe(pParse);
if( v ) sqlite3VdbeAddOp0(v, OP_Expire);
}
}
/*