SQLite

/*
** 2005 July 8
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.5 2005/07/23 14:52:12 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.

    sqlite3VdbeAddOp(v, OP_Close, iIdxCur, 0);

    /* Store the results.  
    **
    ** The result is a single row of the sqlite_stmt1 table.  The first
    ** two columns are the names of the table and index.  The third column
    ** is a string composed of a list of integer statistics about the
    ** index.  The first integer in the list is the total number of entires
    ** in the index.  There is one additional integer in the list for each
    ** column of the table.  This additional integer is a guess of how many
    ** rows of the table the index will select.  If D is the count of distinct
    ** values and K is the total number of rows, then the integer is computed
    ** as:
    **
    **        I = (K+D-1)/D
    **
    ** If K==0 then no entry is made into the sqlite_stat1 table.  
    ** If K>0 then it is always the case the D>0 so division by zero
    ** is never possible.
    */
    sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
    addr = sqlite3VdbeAddOp(v, OP_IfNot, 0, 0);
    sqlite3VdbeAddOp(v, OP_NewRowid, iStatCur, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, pIdx->zName, 0);
    sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, " ", 0);
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
      sqlite3VdbeAddOp(v, OP_MemLoad, iMem+i+1, 0);
      sqlite3VdbeAddOp(v, OP_Add, 0, 0);
      sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
      sqlite3VdbeAddOp(v, OP_MemLoad, iMem+i+1, 0);
      sqlite3VdbeAddOp(v, OP_Divide, 0, 0);
      if( i==nCol-1 ){

        sqlite3VdbeAddOp(v, OP_Concat, nCol*2-1, 0);

      }else{



        sqlite3VdbeAddOp(v, OP_Dup, 1, 0);

      }
    }
    sqlite3VdbeOp3(v, OP_MakeRecord, 3, 0, "ttt", 0);
    sqlite3VdbeAddOp(v, OP_Insert, iStatCur, 0);
    sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
  }
}

    return 0;
  }
  pIndex = sqlite3FindIndex(pInfo->db, argv[0], pInfo->zDatabase);
  if( pIndex==0 ){
    return 0;
  }
  z = argv[1];
  for(i=0; *z && i<=pIndex->nColumn; i++){
    v = 0;
    while( (c=z[0])>='0' && c<='9' ){
      v = v*10 + c - '0';
      z++;
    }
    pIndex->aiRowEst[i] = v;
    if( *z==' ' ) z++;

  HashElem *i;
  char *zSql;

  /* Clear any prior statistics */
  for(i=sqliteHashFirst(&db->aDb[iDb].idxHash); i; i=sqliteHashNext(i)){
    Index *pIdx = sqliteHashData(i);
    int j;
    for(j=0; j<=pIdx->nColumn; j++){
      pIdx->aiRowEst[j] = j<100 ? 1000*(100-j) : 100;
    }
  }

  /* Check to make sure the sqlite_stat1 table existss */
  sInfo.db = db;
  sInfo.zDatabase = db->aDb[iDb].zName;
  if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)==0 ){

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.335 2005/07/23 14:52:12 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.

    pList = sqlite3ExprListAppend(0, 0, &nullId);
    if( pList==0 ) goto exit_create_index;
  }

  /* 
  ** Allocate the index structure. 
  */
  pIndex = sqliteMalloc( sizeof(Index) + strlen(zName) + 1 + sizeof(int) +
                        (sizeof(int)*2 + sizeof(CollSeq*))*pList->nExpr );
  if( sqlite3_malloc_failed ) goto exit_create_index;
  pIndex->aiColumn = (int*)&pIndex->keyInfo.aColl[pList->nExpr];
  pIndex->aiRowEst = &pIndex->aiColumn[pList->nExpr];
  pIndex->zName = (char*)&pIndex->aiRowEst[pList->nExpr+1];
  strcpy(pIndex->zName, zName);
  pIndex->pTable = pTab;
  pIndex->nColumn = pList->nExpr;
  pIndex->onError = onError;
  pIndex->autoIndex = pName==0;
  pIndex->iDb = iDb;

# 2005 July 22
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
# This file implements tests for the ANALYZE command.
#
# $Id: analyze.test,v 1.2 2005/07/23 14:52:12 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# There is nothing to test if ANALYZE is disable for this build.
#
ifcapable {!analyze} {

do_test analyze-3.1 {
  execsql {
    INSERT INTO t1 VALUES(1,2);
    INSERT INTO t1 VALUES(1,3);
    ANALYZE main.t1;
    SELECT idx, stat FROM sqlite_stat1 ORDER BY idx;
  }
} {t1i1 {2 2} t1i2 {2 1} t1i3 {2 2 1}}
do_test analyze-3.2 {
  execsql {
    INSERT INTO t1 VALUES(1,4);
    INSERT INTO t1 VALUES(1,5);
    ANALYZE t1;
    SELECT idx, stat FROM sqlite_stat1 ORDER BY idx;
  }
} {t1i1 {4 4} t1i2 {4 1} t1i3 {4 4 1}}
do_test analyze-3.3 {
  execsql {
    INSERT INTO t1 VALUES(2,5);
    ANALYZE main;
    SELECT idx, stat FROM sqlite_stat1 ORDER BY idx;
  }
} {t1i1 {5 3} t1i2 {5 2} t1i3 {5 3 1}}
do_test analyze-3.4 {
  execsql {
    CREATE TABLE t2 AS SELECT * FROM t1;
    CREATE INDEX t2i1 ON t2(a);
    CREATE INDEX t2i2 ON t2(b);
    CREATE INDEX t2i3 ON t2(a,b);
    ANALYZE;
    SELECT idx, stat FROM sqlite_stat1 ORDER BY idx;
  }
} {t1i1 {5 3} t1i2 {5 2} t1i3 {5 3 1} t2i1 {5 3} t2i2 {5 2} t2i3 {5 3 1}}
do_test analyze-3.5 {
  execsql {
    DROP INDEX t2i3;
    ANALYZE t1;
    SELECT idx, stat FROM sqlite_stat1 ORDER BY idx;
  }
} {t1i1 {5 3} t1i2 {5 2} t1i3 {5 3 1} t2i1 {5 3} t2i2 {5 2} t2i3 {5 3 1}}
do_test analyze-3.6 {
  execsql {
    ANALYZE t2;
    SELECT idx, stat FROM sqlite_stat1 ORDER BY idx;
  }
} {t1i1 {5 3} t1i2 {5 2} t1i3 {5 3 1} t2i1 {5 3} t2i2 {5 2}}
do_test analyze-3.7 {
  execsql {
    DROP INDEX t2i2;
    ANALYZE t2;
    SELECT idx, stat FROM sqlite_stat1 ORDER BY idx;
  }
} {t1i1 {5 3} t1i2 {5 2} t1i3 {5 3 1}}
do_test analyze-3.8 {
  execsql {
    CREATE TABLE t3 AS SELECT a, b, rowid AS c, 'hi' AS d FROM t1;
    CREATE INDEX t3i1 ON t3(a);
    CREATE INDEX t3i2 ON t3(a,b,c,d);
    CREATE INDEX t3i3 ON t3(d,b,c,a);
    DROP TABLE t1;
    DROP TABLE t2;
    ANALYZE;
    SELECT idx, stat FROM sqlite_stat1 ORDER BY idx;
  }
} {t3i1 {5 3} t3i2 {5 3 1 1 1} t3i3 {5 5 2 1 1}}


finish_test