/*
** The VACUUM command is used to clean up the database,
** collapse free space, etc. It is modelled after the VACUUM command
** in PostgreSQL. The VACUUM command works as follows:
**
** (1) Create a new transient database file
** (2) Copy all content from the database being vacuumed into
** the new transient database file
** (3) Copy content from the transient database back into the
** original database.
**
** The transient database requires temporary disk space approximately
** equal to the size of the original database. The copy operation of
** step (3) requires additional temporary disk space approximately equal
** to the size of the original database for the rollback journal.
** Hence, temporary disk space that is approximately 2x the size of the
** original database is required. Every page of the database is written
** approximately 3 times: Once for step (2) and twice for step (3).
** Two writes per page are required in step (3) because the original
** database content must be written into the rollback journal prior to
** overwriting the database with the vacuumed content.
**
** Only 1x temporary space and only 1x writes would be required if
** the copy of step (3) were replaced by deleting the original database
** and renaming the transient database as the original. But that will
** not work if other processes are attached to the original database.
** And a power loss in between deleting the original and renaming the
** transient would cause the database file to appear to be deleted
** following reboot.
*/
void sqlite3Vacuum(Parse *pParse, Token *pNm, Expr *pInto){
Vdbe *v = sqlite3GetVdbe(pParse);
int iDb = 0;
if( v==0 ) goto build_vacuum_end;
if( pNm ){
#ifndef SQLITE_BUG_COMPATIBLE_20160819
/* Default behavior: Report an error if the argument to VACUUM is
** not recognized */
iDb = sqlite3TwoPartName(pParse, pNm, pNm, &pNm);
if( iDb<0 ) goto build_vacuum_end;
#else
/* When SQLITE_BUG_COMPATIBLE_20160819 is defined, unrecognized arguments
** to VACUUM are silently ignored. This is a back-out of a bug fix that
** occurred on 2016-08-19 (https://www.sqlite.org/src/info/083f9e6270).
** The buggy behavior is required for binary compatibility with some
** legacy applications. */
iDb = sqlite3FindDb(pParse->db, pNm);
if( iDb<0 ) iDb = 0;
#endif
}
if( iDb!=1 ){
int iIntoReg = 0;
if( pInto && sqlite3ResolveSelfReference(pParse,0,0,pInto,0)==0 ){
iIntoReg = ++pParse->nMem;
sqlite3ExprCode(pParse, pInto, iIntoReg);
}
sqlite3VdbeAddOp2(v, OP_Vacuum, iDb, iIntoReg);
sqlite3VdbeUsesBtree(v, iDb);
}
build_vacuum_end:
sqlite3ExprDelete(pParse->db, pInto);
return;
}
/*
** Generate code for the ANALYZE command. The parser calls this routine
** when it recognizes an ANALYZE command.
**
** ANALYZE -- 1
** ANALYZE <database> -- 2
** ANALYZE ?<database>.?<tablename> -- 3
**
** 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.
*/
void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){
sqlite3 *db = pParse->db;
int iDb;
int i;
char *z, *zDb;
Table *pTab;
Index *pIdx;
Token *pTableName;
/* Read the database schema. If an error occurs, leave an error message
** and code in pParse and return NULL. */
assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
return;
}
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);
}
}else if( pName2->n==0 ){
/* Form 2: Analyze the database or table named */
iDb = sqlite3FindDb(db, pName1);
if( iDb>=0 ){
analyzeDatabase(pParse, iDb);
}else{
z = sqlite3NameFromToken(db, pName1);
if( z ){
if( (pIdx = sqlite3FindIndex(db, z, 0))!=0 ){
analyzeTable(pParse, pIdx->pTable, pIdx);
}else if( (pTab = sqlite3LocateTable(pParse, 0, z, 0))!=0 ){
analyzeTable(pParse, pTab, 0);
}
sqlite3DbFree(db, z);
}
}
}else{
/* Form 3: Analyze the fully qualified table name */
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pTableName);
if( iDb>=0 ){
zDb = db->aDb[iDb].zName;
z = sqlite3NameFromToken(db, pTableName);
if( z ){
if( (pIdx = sqlite3FindIndex(db, z, zDb))!=0 ){
analyzeTable(pParse, pIdx->pTable, pIdx);
}else if( (pTab = sqlite3LocateTable(pParse, 0, z, zDb))!=0 ){
analyzeTable(pParse, pTab, 0);
}
sqlite3DbFree(db, z);
}
}
}
}
/*
** Connect to or create a dbpagevfs virtual table.
*/
static int dbpageConnect(
sqlite3 *db,
void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVtab,
char **pzErr
){
DbpageTable *pTab = 0;
int rc = SQLITE_OK;
int iDb;
if( argc>=4 ){
Token nm;
sqlite3TokenInit(&nm, (char*)argv[3]);
iDb = sqlite3FindDb(db, &nm);
if( iDb<0 ){
*pzErr = sqlite3_mprintf("no such schema: %s", argv[3]);
return SQLITE_ERROR;
}
}else{
iDb = 0;
}
rc = sqlite3_declare_vtab(db,
"CREATE TABLE x(pgno INTEGER PRIMARY KEY, data BLOB, schema HIDDEN)");
if( rc==SQLITE_OK ){
pTab = (DbpageTable *)sqlite3_malloc64(sizeof(DbpageTable));
if( pTab==0 ) rc = SQLITE_NOMEM_BKPT;
}
assert( rc==SQLITE_OK || pTab==0 );
if( rc==SQLITE_OK ){
Btree *pBt = db->aDb[iDb].pBt;
memset(pTab, 0, sizeof(DbpageTable));
pTab->db = db;
pTab->iDb = iDb;
pTab->pPager = pBt ? sqlite3BtreePager(pBt) : 0;
}
*ppVtab = (sqlite3_vtab*)pTab;
return rc;
}
/*
** Connect to or create a statvfs virtual table.
*/
static int statConnect(
sqlite3 *db,
void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVtab,
char **pzErr
){
StatTable *pTab = 0;
int rc = SQLITE_OK;
int iDb;
if( argc>=4 ){
Token nm;
sqlite3TokenInit(&nm, (char*)argv[3]);
iDb = sqlite3FindDb(db, &nm);
if( iDb<0 ){
*pzErr = sqlite3_mprintf("no such database: %s", argv[3]);
return SQLITE_ERROR;
}
}else{
iDb = 0;
}
rc = sqlite3_declare_vtab(db, VTAB_SCHEMA);
if( rc==SQLITE_OK ){
pTab = (StatTable *)sqlite3_malloc64(sizeof(StatTable));
if( pTab==0 ) rc = SQLITE_NOMEM_BKPT;
}
assert( rc==SQLITE_OK || pTab==0 );
if( rc==SQLITE_OK ){
memset(pTab, 0, sizeof(StatTable));
pTab->db = db;
pTab->iDb = iDb;
}
*ppVtab = (sqlite3_vtab*)pTab;
return rc;
}
