SQLite

Check-in [877d5558b1]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Answer queries for a particular rowid in a full-text table by looking up that rowid directly rather than by performing a table scan. (CVS 3407)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 877d5558b1a6f65201b1825336935b146583bffa
User & Date: adamd 2006-09-12 23:36:45.000
Context
2006-09-13
02:18
Allow virtual tables to contain multiple full-text-indexed columns. Added a magic column "_all" which can be used for querying all columns in a table at once.

For now, each posting list stores position/offset information for multiple columns. We may implement separate posting lists for separate columns at some future point. (CVS 3408) (check-in: 366a70b086 user: adamd tags: trunk)

2006-09-12
23:36
Answer queries for a particular rowid in a full-text table by looking up that rowid directly rather than by performing a table scan. (CVS 3407) (check-in: 877d5558b1 user: adamd tags: trunk)
2006-09-11
23:45
Add support for IF EXISTS on CREATE/DROP TRIGGER/VIEW. Ticket #1899. (CVS 3406) (check-in: e4fe736cfb user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to ext/fts1/fts1.c.
746
747
748
749
750
751
752

753

754

755
756
757
758
759
760
761
  rc = sqlite3_prepare(db, zCommand, -1, ppStmt, NULL);
  free(zCommand);
  return rc;
}

/* end utility functions */


#define QUERY_GENERIC 0

#define QUERY_FULLTEXT 1


/* TODO(shess) CHUNK_MAX controls how much data we allow in segment 0
** before we start aggregating into larger segments.  Lower CHUNK_MAX
** means that for a given input we have more individual segments per
** term, which means more rows in the table and a bigger index (due to
** both more rows and bigger rowids).  But it also reduces the average
** cost of adding new elements to the segment 0 doclist, and it seems







>
|
>
|
>







746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
  rc = sqlite3_prepare(db, zCommand, -1, ppStmt, NULL);
  free(zCommand);
  return rc;
}

/* end utility functions */

typedef enum QueryType {
  QUERY_GENERIC,     /* table scan */
  QUERY_ROWID,       /* lookup by rowid */
  QUERY_FULLTEXT    /* full-text search */
} QueryType;

/* TODO(shess) CHUNK_MAX controls how much data we allow in segment 0
** before we start aggregating into larger segments.  Lower CHUNK_MAX
** means that for a given input we have more individual segments per
** term, which means more rows in the table and a bigger index (due to
** both more rows and bigger rowids).  But it also reduces the average
** cost of adding new elements to the segment 0 doclist, and it seems
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
  ** open.
  */
  sqlite3_stmt *pFulltextStatements[MAX_STMT];
} fulltext_vtab;

typedef struct fulltext_cursor {
  sqlite3_vtab_cursor base;
  int iCursorType;  /* QUERY_GENERIC or QUERY_FULLTEXT */

  sqlite3_stmt *pStmt;

  int eof;

  /* The following is used only when iCursorType == QUERY_FULLTEXT. */
  DocListReader result;
} fulltext_cursor;

static struct fulltext_vtab *cursor_vtab(fulltext_cursor *c){
  return (fulltext_vtab *) c->base.pVtab;
}

static const sqlite3_module fulltextModule;   /* forward declaration */







|


<


<
|







816
817
818
819
820
821
822
823
824
825

826
827

828
829
830
831
832
833
834
835
  ** open.
  */
  sqlite3_stmt *pFulltextStatements[MAX_STMT];
} fulltext_vtab;

typedef struct fulltext_cursor {
  sqlite3_vtab_cursor base;
  QueryType iCursorType;

  sqlite3_stmt *pStmt;

  int eof;


  DocListReader result;  /* used when iCursorType == QUERY_FULLTEXT */ 
} fulltext_cursor;

static struct fulltext_vtab *cursor_vtab(fulltext_cursor *c){
  return (fulltext_vtab *) c->base.pVtab;
}

static const sqlite3_module fulltextModule;   /* forward declaration */
1452
1453
1454
1455
1456
1457
1458

1459



1460
1461


1462
1463
1464



1465

1466
1467
1468
1469
1470
1471
1472
 * haven't implemented phrase searches or OR yet. */
static int fulltextBestIndex(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
  int i;

  for(i=0; i<pInfo->nConstraint; ++i){
    const struct sqlite3_index_constraint *pConstraint;
    pConstraint = &pInfo->aConstraint[i];

    if( pConstraint->iColumn==0 &&



        pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH &&
        pConstraint->usable ){   /* a full-text search */


      pInfo->aConstraintUsage[i].argvIndex = 1;
      pInfo->aConstraintUsage[i].omit = 1;
      pInfo->idxNum = QUERY_FULLTEXT;



      pInfo->estimatedCost = 1.0;   /* an arbitrary value for now */

      return SQLITE_OK;
    }
  }
  pInfo->idxNum = QUERY_GENERIC;
  TRACE(("FTS1 BestIndex\n"));
  return SQLITE_OK;
}







>
|
>
>
>
|
|
>
>


|
>
>
>
|
>







1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
 * haven't implemented phrase searches or OR yet. */
static int fulltextBestIndex(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
  int i;

  for(i=0; i<pInfo->nConstraint; ++i){
    const struct sqlite3_index_constraint *pConstraint;
    pConstraint = &pInfo->aConstraint[i];
    if( pConstraint->usable ) {
      if( pConstraint->iColumn==-1 &&
          pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){
        pInfo->idxNum = QUERY_ROWID;      /* lookup by rowid */
      } else if( pConstraint->iColumn==0 &&
                 pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
        pInfo->idxNum = QUERY_FULLTEXT;   /* full-text search */
      } else continue;

      pInfo->aConstraintUsage[i].argvIndex = 1;
      pInfo->aConstraintUsage[i].omit = 1;

      /* An arbitrary value for now.
       * TODO: Perhaps rowid matches should be considered cheaper than
       * full-text searches. */
      pInfo->estimatedCost = 1.0;   

      return SQLITE_OK;
    }
  }
  pInfo->idxNum = QUERY_GENERIC;
  TRACE(("FTS1 BestIndex\n"));
  return SQLITE_OK;
}
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564

static int fulltextNext(sqlite3_vtab_cursor *pCursor){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;
  sqlite_int64 iDocid;
  int rc;

  TRACE(("FTS1 Next %p\n", pCursor));
  switch( c->iCursorType ){
    case QUERY_GENERIC:
      /* TODO(shess) Handle SQLITE_SCHEMA AND SQLITE_BUSY. */
      rc = sqlite3_step(c->pStmt);
      switch( rc ){
        case SQLITE_ROW:
          c->eof = 0;
          return SQLITE_OK;
        case SQLITE_DONE:
          c->eof = 1;
          return SQLITE_OK;
        default:
          c->eof = 1;
          return rc;
      }
    case QUERY_FULLTEXT:
      rc = sqlite3_reset(c->pStmt);
      if( rc!=SQLITE_OK ) return rc;

      iDocid = nextValidDocid(&c->result);
      if( iDocid==0 ){
        c->eof = 1;
        return SQLITE_OK;
      }
      rc = sqlite3_bind_int64(c->pStmt, 1, iDocid);
      if( rc!=SQLITE_OK ) return rc;
      /* TODO(shess) Handle SQLITE_SCHEMA AND SQLITE_BUSY. */
      rc = sqlite3_step(c->pStmt);
      if( rc==SQLITE_ROW ){   /* the case we expect */
        c->eof = 0;
        return SQLITE_OK;
      }
      /* an error occurred; abort */
      return rc==SQLITE_DONE ? SQLITE_ERROR : rc;
    default:
      assert( 0 );
      return SQLITE_ERROR;  /* not reached */
  }
}

/* A single term in a query is represented by an instances of
** the following structure.
*/
typedef struct QueryTerm {







|
<
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|

|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<
<
<







1525
1526
1527
1528
1529
1530
1531
1532

1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564



1565
1566
1567
1568
1569
1570
1571

static int fulltextNext(sqlite3_vtab_cursor *pCursor){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;
  sqlite_int64 iDocid;
  int rc;

  TRACE(("FTS1 Next %p\n", pCursor));
  if( c->iCursorType != QUERY_FULLTEXT ){

    /* TODO(shess) Handle SQLITE_SCHEMA AND SQLITE_BUSY. */
    rc = sqlite3_step(c->pStmt);
    switch( rc ){
      case SQLITE_ROW:
        c->eof = 0;
        return SQLITE_OK;
      case SQLITE_DONE:
        c->eof = 1;
        return SQLITE_OK;
      default:
        c->eof = 1;
        return rc;
    }
  } else {  /* full-text query */
    rc = sqlite3_reset(c->pStmt);
    if( rc!=SQLITE_OK ) return rc;

    iDocid = nextValidDocid(&c->result);
    if( iDocid==0 ){
      c->eof = 1;
      return SQLITE_OK;
    }
    rc = sqlite3_bind_int64(c->pStmt, 1, iDocid);
    if( rc!=SQLITE_OK ) return rc;
    /* TODO(shess) Handle SQLITE_SCHEMA AND SQLITE_BUSY. */
    rc = sqlite3_step(c->pStmt);
    if( rc==SQLITE_ROW ){   /* the case we expect */
      c->eof = 0;
      return SQLITE_OK;
    }
    /* an error occurred; abort */
    return rc==SQLITE_DONE ? SQLITE_ERROR : rc;



  }
}

/* A single term in a query is represented by an instances of
** the following structure.
*/
typedef struct QueryTerm {
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838

1839








1840
1841
1842
1843
1844
1845
1846
1847
1848
1849

1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865

static int fulltextFilter(sqlite3_vtab_cursor *pCursor,
                          int idxNum, const char *idxStr,
                          int argc, sqlite3_value **argv){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;
  fulltext_vtab *v = cursor_vtab(c);
  int rc;
  const char *zStatement;

  TRACE(("FTS1 Filter %p\n",pCursor));
  c->iCursorType = idxNum;
  switch( idxNum ){
    case QUERY_GENERIC:

      zStatement = "select rowid, content from %_content";








      break;

    case QUERY_FULLTEXT:   /* full-text search */
    {
      const char *zQuery = (const char *)sqlite3_value_text(argv[0]);
      DocList *pResult;
      assert( argc==1 );
      rc = fulltextQuery(v, zQuery, -1, &pResult);
      if( rc!=SQLITE_OK ) return rc;
      readerInit(&c->result, pResult);

      zStatement = "select rowid, content from %_content where rowid = ?";
      break;
    }

    default:
      assert( 0 );
  }

  rc = sql_prepare(v->db, v->zName, &c->pStmt, zStatement);
  if( rc!=SQLITE_OK ) return rc;

  return fulltextNext(pCursor);
}

static int fulltextEof(sqlite3_vtab_cursor *pCursor){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;







<





>
|
>
>
>
>
>
>
>
>










>
|







<







1833
1834
1835
1836
1837
1838
1839

1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873

1874
1875
1876
1877
1878
1879
1880

static int fulltextFilter(sqlite3_vtab_cursor *pCursor,
                          int idxNum, const char *idxStr,
                          int argc, sqlite3_value **argv){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;
  fulltext_vtab *v = cursor_vtab(c);
  int rc;


  TRACE(("FTS1 Filter %p\n",pCursor));
  c->iCursorType = idxNum;
  switch( idxNum ){
    case QUERY_GENERIC:
      rc = sql_prepare(v->db, v->zName, &c->pStmt,
                       "select rowid, content from %_content");
      break;

    case QUERY_ROWID:
      rc = sql_prepare(v->db, v->zName, &c->pStmt,
                       "select rowid, content from %_content where rowid = ?");
      if( rc!=SQLITE_OK ) return rc;

      rc = sqlite3_bind_int64(c->pStmt, 1, sqlite3_value_int64(argv[0]));
      break;

    case QUERY_FULLTEXT:   /* full-text search */
    {
      const char *zQuery = (const char *)sqlite3_value_text(argv[0]);
      DocList *pResult;
      assert( argc==1 );
      rc = fulltextQuery(v, zQuery, -1, &pResult);
      if( rc!=SQLITE_OK ) return rc;
      readerInit(&c->result, pResult);
      rc = sql_prepare(v->db, v->zName, &c->pStmt,
                       "select rowid, content from %_content where rowid = ?");
      break;
    }

    default:
      assert( 0 );
  }


  if( rc!=SQLITE_OK ) return rc;

  return fulltextNext(pCursor);
}

static int fulltextEof(sqlite3_vtab_cursor *pCursor){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;