SQLite

**
**   (A)    word MATCH $str
**   (B)    langid == $langid
**   (C)    top = $top
**   (D)    scope = $scope
**   (E)    distance < $distance
**   (F)    distance <= $distance
**   (G)    rowid = $rowid
**
** The plan number is a bit mask formed with these bits:
**
**   0x01   (A) is found
**   0x02   (B) is found
**   0x04   (C) is found
**   0x08   (D) is found
**   0x10   (E) is found
**   0x20   (F) is found
**   0x40   (G) is found
**
** filter.argv[*] values contains $str, $langid, $top, $scope and $rowid
** if specified and in that order.
*/
static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int iPlan = 0;
  int iLangTerm = -1;
  int iTopTerm = -1;
  int iScopeTerm = -1;
  int iDistTerm = -1;
  int iRowidTerm = -1;
  int i;
  const struct sqlite3_index_constraint *pConstraint;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;

    /* Terms of the form:  word MATCH $str */

     && pConstraint->iColumn==SPELLFIX_COL_DISTANCE
     && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT
          || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE)
    ){
      iPlan |= pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ? 16 : 32;
      iDistTerm = i;
    }

    /* Terms of the form:  distance < $dist or distance <= $dist */
    if( (iPlan & 64)==0
     && pConstraint->iColumn<0
     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
    ){
      iPlan |= 64;
      iRowidTerm = i;
    }
  }
  if( iPlan&1 ){
    int idx = 2;
    pIdxInfo->idxNum = iPlan;
    if( pIdxInfo->nOrderBy==1
     && pIdxInfo->aOrderBy[0].iColumn==SPELLFIX_COL_SCORE
     && pIdxInfo->aOrderBy[0].desc==0

      pIdxInfo->aConstraintUsage[iScopeTerm].omit = 1;
    }
    if( iPlan&(16|32) ){
      pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = idx++;
      pIdxInfo->aConstraintUsage[iDistTerm].omit = 1;
    }
    pIdxInfo->estimatedCost = 1e5;
  }else if( (iPlan & 64) ){
    pIdxInfo->idxNum = 64;
    pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;
    pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;
    pIdxInfo->estimatedCost = 5;
  }else{
    pIdxInfo->idxNum = 0;
    pIdxInfo->estimatedCost = 1e50;
  }
  return SQLITE_OK;
}

*/
static int spellfix1FilterForFullScan(
  spellfix1_cursor *pCur,
  int idxNum,
  int argc,
  sqlite3_value **argv
){
  int rc = SQLITE_OK;
  char *zSql;
  spellfix1_vtab *pVTab = pCur->pVTab;
  spellfix1ResetCursor(pCur);
  assert( idxNum==0 || idxNum==64 );
  zSql = sqlite3_mprintf(
     "SELECT word, rank, NULL, langid, id FROM \"%w\".\"%w_vocab\"%s",
     pVTab->zDbName, pVTab->zTableName,
     ((idxNum & 64) ? " WHERE rowid=?" : "")
  );
  if( zSql==0 ) return SQLITE_NOMEM;
  rc = sqlite3_prepare_v2(pVTab->db, zSql, -1, &pCur->pFullScan, 0);
  sqlite3_free(zSql);
  if( rc==SQLITE_OK && (idxNum & 64) ){
    assert( argc==1 );
    rc = sqlite3_bind_value(pCur->pFullScan, 1, argv[0]);
  }
  pCur->nRow = pCur->iRow = 0;
  if( rc==SQLITE_OK ){
    rc = sqlite3_step(pCur->pFullScan);
    if( rc==SQLITE_ROW ){ pCur->iRow = -1; rc = SQLITE_OK; }
    if( rc==SQLITE_DONE ){ rc = SQLITE_OK; }
  }else{
    pCur->iRow = 0;

  5   kusher     {kosher 16}
} {
  do_execsql_test 5.1.$tn {
    SELECT word, distance FROM t3 WHERE word MATCH $word
     ORDER BY score, word LIMIT 1
  } $res
}

#-------------------------------------------------------------------------
# Try some queries by rowid.
#
do_execsql_test 6.1.1 {
  SELECT word FROM t3 WHERE rowid = 10;
} {keener}
do_execsql_test 6.1.2 {
  SELECT word, distance FROM t3 WHERE rowid = 10;
} {keener {}}
do_execsql_test 6.1.3 {
  SELECT word, distance FROM t3 WHERE rowid = 10 AND word MATCH 'kiiner';
} {keener 300}

proc trace_callback {sql} {
  if {[string range $sql 0 2] == "-- "} {
    lappend ::trace [string range $sql 3 end]
  }
}

proc do_tracesql_test {tn sql {res {}}} {
  set ::trace [list]
  uplevel [list do_test $tn [subst -nocommands {
    set vals [execsql {$sql}]
    concat [set vals] [set ::trace]
  }] [list {*}$res]]
}

db trace trace_callback
do_tracesql_test 6.2.1 {
  SELECT word FROM t3 WHERE rowid = 10;
} {keener
  {SELECT word, rank, NULL, langid, id FROM "main"."t3_vocab" WHERE rowid=?}
}
do_tracesql_test 6.2.2 {
  SELECT word, distance FROM t3 WHERE rowid = 10;
} {keener {}
  {SELECT word, rank, NULL, langid, id FROM "main"."t3_vocab" WHERE rowid=?}
}
do_tracesql_test 6.2.3 {
  SELECT word, distance FROM t3 WHERE rowid = 10 AND word MATCH 'kiiner';
} {keener 300
  {SELECT id, word, rank, k1  FROM "main"."t3_vocab" WHERE langid=0 AND k2>=?1 AND k2<?2}
}




finish_test