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Overview
Comment:Do not generate sqlite_stat1 entries for empty tables when running ANALYZE. Ticket [83ea97620bd31016451]
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SHA1: 3a27af5b3c688c651ba1fae261026ef77b7ff5e3
User & Date: drh 2011-03-30 14:54:05
Context
2011-03-30
19:08
Further tests for os_unix.c. check-in: a84f7711 user: dan tags: trunk
14:54
Do not generate sqlite_stat1 entries for empty tables when running ANALYZE. Ticket [83ea97620bd31016451] check-in: 3a27af5b user: drh tags: trunk
2011-03-29
18:28
Add tests to syscall.test and sysfault.test. check-in: 3d2de011 user: dan tags: trunk
Changes
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Changes to src/analyze.c.

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  Index *pIdx;                 /* An index to being analyzed */
  int iIdxCur;                 /* Cursor open on index being analyzed */
  Vdbe *v;                     /* The virtual machine being built up */
  int i;                       /* Loop counter */
  int topOfLoop;               /* The top of the loop */
  int endOfLoop;               /* The end of the loop */
  int addr = 0;                /* 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 */
  int regSampleno = iMem++;    /* Register containing next sample number */
  int regCol = iMem++;         /* Content of a column analyzed table */
  int regRec = iMem++;         /* Register holding completed record */
  int regTemp = iMem++;        /* Temporary use register */
................................................................................
    **        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.
    */
    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);
      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
................................................................................
  ** 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 loaded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){







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  Index *pIdx;                 /* An index to being analyzed */
  int iIdxCur;                 /* Cursor open on index being analyzed */
  Vdbe *v;                     /* The virtual machine being built up */
  int i;                       /* Loop counter */
  int topOfLoop;               /* The top of the loop */
  int endOfLoop;               /* The end of the loop */
  int addr = 0;                /* The address of an instruction */
  int jZeroRows = -1;          /* 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 */
  int regSampleno = iMem++;    /* Register containing next sample number */
  int regCol = iMem++;         /* Content of a column analyzed table */
  int regRec = iMem++;         /* Register holding completed record */
  int regTemp = iMem++;        /* Temporary use register */
................................................................................
    **        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.
    */
    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);
      sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp);
      sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1);
................................................................................
  ** 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);
    jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regSampleno);
  }else{


    sqlite3VdbeJumpHere(v, jZeroRows);
    jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto);
  }
  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;

  sqlite3VdbeJumpHere(v, jZeroRows);

}

/*
** Generate code that will cause the most recent index analysis to
** be loaded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){

Changes to src/vdbeaux.c.

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}

/*
** Change the P2 operand of instruction addr so that it points to
** the address of the next instruction to be coded.
*/
void sqlite3VdbeJumpHere(Vdbe *p, int addr){
  sqlite3VdbeChangeP2(p, addr, p->nOp);
}


/*
** If the input FuncDef structure is ephemeral, then free it.  If
** the FuncDef is not ephermal, then do nothing.
*/







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}

/*
** Change the P2 operand of instruction addr so that it points to
** the address of the next instruction to be coded.
*/
void sqlite3VdbeJumpHere(Vdbe *p, int addr){
  if( addr>=0 ) sqlite3VdbeChangeP2(p, addr, p->nOp);
}


/*
** If the input FuncDef structure is ephemeral, then free it.  If
** the FuncDef is not ephermal, then do nothing.
*/

Changes to test/analyze.test.

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    ANALYZE main.t1;
  }
} {0 {}}
do_test analyze-1.11 {
  execsql {
    SELECT * FROM sqlite_stat1
  }
} {t1 {} 0}
do_test analyze-1.12 {
  catchsql {
    ANALYZE t1;
  }
} {0 {}}
do_test analyze-1.13 {
  execsql {
    SELECT * FROM sqlite_stat1
  }
} {t1 {} 0}

# Create some indices that can be analyzed.  But do not yet add
# data.  Without data in the tables, no analysis is done.
#
do_test analyze-2.1 {
  execsql {
    CREATE INDEX t1i1 ON t1(a);
    ANALYZE main.t1;
    SELECT * FROM sqlite_stat1 ORDER BY idx;
  }
} {t1 {} 0}
do_test analyze-2.2 {
  execsql {
    CREATE INDEX t1i2 ON t1(b);
    ANALYZE t1;
    SELECT * FROM sqlite_stat1 ORDER BY idx;
  }
} {t1 {} 0}
do_test analyze-2.3 {
  execsql {
    CREATE INDEX t1i3 ON t1(a,b);
    ANALYZE main;
    SELECT * FROM sqlite_stat1 ORDER BY idx;
  }
} {t1 {} 0}

# Start adding data to the table.  Verify that the analysis
# is done correctly.
#
do_test analyze-3.1 {
  execsql {
    INSERT INTO t1 VALUES(1,2);







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    ANALYZE main.t1;
  }
} {0 {}}
do_test analyze-1.11 {
  execsql {
    SELECT * FROM sqlite_stat1
  }
} {}
do_test analyze-1.12 {
  catchsql {
    ANALYZE t1;
  }
} {0 {}}
do_test analyze-1.13 {
  execsql {
    SELECT * FROM sqlite_stat1
  }
} {}

# Create some indices that can be analyzed.  But do not yet add
# data.  Without data in the tables, no analysis is done.
#
do_test analyze-2.1 {
  execsql {
    CREATE INDEX t1i1 ON t1(a);
    ANALYZE main.t1;
    SELECT * FROM sqlite_stat1 ORDER BY idx;
  }
} {}
do_test analyze-2.2 {
  execsql {
    CREATE INDEX t1i2 ON t1(b);
    ANALYZE t1;
    SELECT * FROM sqlite_stat1 ORDER BY idx;
  }
} {}
do_test analyze-2.3 {
  execsql {
    CREATE INDEX t1i3 ON t1(a,b);
    ANALYZE main;
    SELECT * FROM sqlite_stat1 ORDER BY idx;
  }
} {}

# Start adding data to the table.  Verify that the analysis
# is done correctly.
#
do_test analyze-3.1 {
  execsql {
    INSERT INTO t1 VALUES(1,2);

Changes to test/analyze6.test.

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# FROM clause.
#
do_test analyze6-1.2 {
  eqp {SELECT count(*) FROM cat, ev WHERE x=y}
} {0 0 0 {SCAN TABLE cat (~16 rows)} 0 1 1 {SEARCH TABLE ev USING COVERING INDEX evy (y=?) (~32 rows)}}


















































finish_test







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# FROM clause.
#
do_test analyze6-1.2 {
  eqp {SELECT count(*) FROM cat, ev WHERE x=y}
} {0 0 0 {SCAN TABLE cat (~16 rows)} 0 1 1 {SEARCH TABLE ev USING COVERING INDEX evy (y=?) (~32 rows)}}


# Ticket [83ea97620bd3101645138b7b0e71c12c5498fe3d] 2011-03-30
# If ANALYZE is run on an empty table, make sure indices are used
# on the table.
#
do_test analyze6-2.1 {
  execsql {
    CREATE TABLE t201(x INTEGER PRIMARY KEY, y UNIQUE, z);
    CREATE INDEX t201z ON t201(z);
    ANALYZE;
  }
  eqp {SELECT * FROM t201 WHERE z=5}
} {0 0 0 {SEARCH TABLE t201 USING INDEX t201z (z=?) (~10 rows)}}
do_test analyze6-2.2 {
  eqp {SELECT * FROM t201 WHERE y=5}
} {0 0 0 {SEARCH TABLE t201 USING INDEX sqlite_autoindex_t201_1 (y=?) (~1 rows)}}
do_test analyze6-2.3 {
  eqp {SELECT * FROM t201 WHERE x=5}
} {0 0 0 {SEARCH TABLE t201 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}}
do_test analyze6-2.4 {
  execsql {
    INSERT INTO t201 VALUES(1,2,3);
    ANALYZE t201;
  }
  eqp {SELECT * FROM t201 WHERE z=5}
} {0 0 0 {SEARCH TABLE t201 USING INDEX t201z (z=?) (~10 rows)}}
do_test analyze6-2.5 {
  eqp {SELECT * FROM t201 WHERE y=5}
} {0 0 0 {SEARCH TABLE t201 USING INDEX sqlite_autoindex_t201_1 (y=?) (~1 rows)}}
do_test analyze6-2.6 {
  eqp {SELECT * FROM t201 WHERE x=5}
} {0 0 0 {SEARCH TABLE t201 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}}
do_test analyze6-2.7 {
  execsql {
    INSERT INTO t201 VALUES(4,5,7);
    INSERT INTO t201 SELECT x+100, y+100, z+100 FROM t201;
    INSERT INTO t201 SELECT x+200, y+200, z+200 FROM t201;
    INSERT INTO t201 SELECT x+400, y+400, z+400 FROM t201;
    ANALYZE t201;
  }
  eqp {SELECT * FROM t201 WHERE z=5}
} {0 0 0 {SEARCH TABLE t201 USING INDEX t201z (z=?) (~10 rows)}}
do_test analyze6-2.8 {
  eqp {SELECT * FROM t201 WHERE y=5}
} {0 0 0 {SEARCH TABLE t201 USING INDEX sqlite_autoindex_t201_1 (y=?) (~1 rows)}}
do_test analyze6-2.9 {
  eqp {SELECT * FROM t201 WHERE x=5}
} {0 0 0 {SEARCH TABLE t201 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}}

finish_test

Changes to test/where3.test.

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# if held until an inner loop.
# 
do_execsql_test where3-3.0 {
  CREATE TABLE t301(a INTEGER PRIMARY KEY,b,c);
  CREATE INDEX t301c ON t301(c);
  INSERT INTO t301 VALUES(1,2,3);
  CREATE TABLE t302(x, y);

  ANALYZE;
  explain query plan SELECT * FROM t302, t301 WHERE t302.x=5 AND t301.a=t302.y;
} {
  0 0 0 {SCAN TABLE t302 (~1 rows)} 
  0 1 1 {SEARCH TABLE t301 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
}
do_execsql_test where3-3.1 {
................................................................................
      AND bbb.parent = 4
    ORDER BY bbb.title COLLATE NOCASE ASC;
} {
  0 0 1 {SEARCH TABLE aaa USING INDEX aaa_333 (fk=?) (~10 rows)} 
  0 1 0 {SEARCH TABLE aaa AS bbb USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)} 
  0 0 0 {USE TEMP B-TREE FOR ORDER BY}
}


finish_test







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# if held until an inner loop.
# 
do_execsql_test where3-3.0 {
  CREATE TABLE t301(a INTEGER PRIMARY KEY,b,c);
  CREATE INDEX t301c ON t301(c);
  INSERT INTO t301 VALUES(1,2,3);
  CREATE TABLE t302(x, y);
  INSERT INTO t302 VALUES(4,5);
  ANALYZE;
  explain query plan SELECT * FROM t302, t301 WHERE t302.x=5 AND t301.a=t302.y;
} {
  0 0 0 {SCAN TABLE t302 (~1 rows)} 
  0 1 1 {SEARCH TABLE t301 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
}
do_execsql_test where3-3.1 {
................................................................................
      AND bbb.parent = 4
    ORDER BY bbb.title COLLATE NOCASE ASC;
} {
  0 0 1 {SEARCH TABLE aaa USING INDEX aaa_333 (fk=?) (~10 rows)} 
  0 1 0 {SEARCH TABLE aaa AS bbb USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)} 
  0 0 0 {USE TEMP B-TREE FOR ORDER BY}
}


finish_test