SQLite

  int argc,                       /* Number of elements in argv array */
  const char * const *argv,       /* xCreate/xConnect argument array */
  sqlite3_vtab **ppVtab,          /* OUT: New sqlite3_vtab object */
  char **pzErr                    /* OUT: sqlite3_malloc'd error message */
){
  return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);
}

/*
** Set the pIdxInfo->estimatedRows variable to nRow. Unless this
** extension is currently being used by a version of SQLite too old to
** support estimatedRows. In that case this function is a no-op.
*/
static void setEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
#if SQLITE_VERSION_NUMBER>=3008002
  if( sqlite3_libversion_number()>=3008002 ){
    pIdxInfo->estimatedRows = nRow;
  }
#endif
}

/* 
** Implementation of the xBestIndex method for FTS3 tables. There
** are three possible strategies, in order of preference:
**
**   1. Direct lookup by rowid or docid. 
**   2. Full-text search using a MATCH operator on a non-docid column.

  ** strategy is possible.
  */
  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
  pInfo->estimatedCost = 5000000;
  for(i=0; i<pInfo->nConstraint; i++){
    int bDocid;                 /* True if this constraint is on docid */
    struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
    if( pCons->usable==0 ){
      if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
        /* There exists an unusable MATCH constraint. This means that if
        ** the planner does elect to use the results of this call as part
        ** of the overall query plan the user will see an "unable to use
        ** function MATCH in the requested context" error. To discourage
        ** this, return a very high cost here.  */
        pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
        pInfo->estimatedCost = 1e50;
        setEstimatedRows(pInfo, ((sqlite3_int64)1) << 50);
        return SQLITE_OK;
      }
      continue;
    }

    bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1);

    /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */
    if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){
      pInfo->idxNum = FTS3_DOCID_SEARCH;
      pInfo->estimatedCost = 1.0;

# 2014 January 4
#
# 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.  The
# focus of this script is testing the FTS3 module.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix fts3join

# If SQLITE_ENABLE_FTS3 is defined, omit this file.
ifcapable !fts3 {
  finish_test
  return
}

do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE ft1 USING fts4(x);
  INSERT INTO ft1 VALUES('aaa aaa');
  INSERT INTO ft1 VALUES('aaa bbb');
  INSERT INTO ft1 VALUES('bbb aaa');
  INSERT INTO ft1 VALUES('bbb bbb');

  CREATE TABLE t1(id, y);
  INSERT INTO t1 VALUES(1, 'aaa');
  INSERT INTO t1 VALUES(2, 'bbb');
}

do_execsql_test 1.1 {
  SELECT docid FROM ft1, t1 WHERE ft1 MATCH y AND id=1;
} {1 2 3}

do_execsql_test 1.2 {
  SELECT docid FROM ft1, t1 WHERE ft1 MATCH y AND id=1 ORDER BY docid;
} {1 2 3}

do_execsql_test 2.0 {
  CREATE VIRTUAL TABLE ft2 USING fts4(x);
  CREATE VIRTUAL TABLE ft3 USING fts4(y);

  INSERT INTO ft2 VALUES('abc');
  INSERT INTO ft2 VALUES('def');
  INSERT INTO ft3 VALUES('ghi');
  INSERT INTO ft3 VALUES('abc');
}

do_execsql_test 2.1 { SELECT * FROM ft2, ft3 WHERE x MATCH y; } {abc abc}
do_execsql_test 2.2 { SELECT * FROM ft2, ft3 WHERE y MATCH x; } {abc abc}
do_execsql_test 2.3 { SELECT * FROM ft3, ft2 WHERE x MATCH y; } {abc abc}
do_execsql_test 2.4 { SELECT * FROM ft3, ft2 WHERE y MATCH x; } {abc abc}

do_catchsql_test 2.5 { 
  SELECT * FROM ft3, ft2 WHERE y MATCH x AND x MATCH y; 
} {1 {unable to use function MATCH in the requested context}}

finish_test