/ Check-in [4372ad64]
Login

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

Overview
Comment:Update the generate_series() table-valued function to make use of the new SQLITE_CONSTRAINT return from xBestIndex.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256: 4372ad644dda5a1fa46b6b6070092320c835439b41f598cbc041e9deef786988
User & Date: drh 2018-11-16 15:08:31
Context
2018-11-16
15:41
Add an assert() to the generate_series virtual table to verify assumptions about the design. check-in: cd13b499 user: drh tags: trunk
15:08
Update the generate_series() table-valued function to make use of the new SQLITE_CONSTRAINT return from xBestIndex. check-in: 4372ad64 user: drh tags: trunk
14:36
In order to avoid exporting a symbol, use a macro instead of a function to replace sqlite3_complete() in the shell code when SQLITE_OMIT_COMPLETE is defined. check-in: d584a0cb user: dan tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to ext/misc/series.c.

309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
...
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
**  (4)  step = $value   -- constraint exists
**  (8)  output in descending order
*/
static int seriesBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;                 /* Loop over constraints */
  int idxNum = 0;        /* The query plan bitmask */
  int startIdx = -1;     /* Index of the start= constraint, or -1 if none */
  int stopIdx = -1;      /* Index of the stop= constraint, or -1 if none */
  int stepIdx = -1;      /* Index of the step= constraint, or -1 if none */
  int nArg = 0;          /* Number of arguments that seriesFilter() expects */

  const struct sqlite3_index_constraint *pConstraint;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    switch( pConstraint->iColumn ){
      case SERIES_COLUMN_START:
        startIdx = i;
        idxNum |= 1;
        break;
      case SERIES_COLUMN_STOP:
        stopIdx = i;
        idxNum |= 2;
        break;
      case SERIES_COLUMN_STEP:
        stepIdx = i;
        idxNum |= 4;
        break;
    }
  }
  if( startIdx>=0 ){
    pIdxInfo->aConstraintUsage[startIdx].argvIndex = ++nArg;
    pIdxInfo->aConstraintUsage[startIdx].omit= !SQLITE_SERIES_CONSTRAINT_VERIFY;
  }
  if( stopIdx>=0 ){
    pIdxInfo->aConstraintUsage[stopIdx].argvIndex = ++nArg;
    pIdxInfo->aConstraintUsage[stopIdx].omit = !SQLITE_SERIES_CONSTRAINT_VERIFY;
  }
  if( stepIdx>=0 ){
    pIdxInfo->aConstraintUsage[stepIdx].argvIndex = ++nArg;
    pIdxInfo->aConstraintUsage[stepIdx].omit = !SQLITE_SERIES_CONSTRAINT_VERIFY;
  }
  if( (idxNum & 3)==3 ){
    /* Both start= and stop= boundaries are available.  This is the 
    ** the preferred case */
    pIdxInfo->estimatedCost = (double)(2 - ((idxNum&4)!=0));
    pIdxInfo->estimatedRows = 1000;
    if( pIdxInfo->nOrderBy==1 ){
................................................................................
      if( pIdxInfo->aOrderBy[0].desc ) idxNum |= 8;
      pIdxInfo->orderByConsumed = 1;
    }
  }else{
    /* If either boundary is missing, we have to generate a huge span
    ** of numbers.  Make this case very expensive so that the query
    ** planner will work hard to avoid it. */
    pIdxInfo->estimatedCost = (double)2147483647;
    pIdxInfo->estimatedRows = 2147483647;
  }
  pIdxInfo->idxNum = idxNum;
  return SQLITE_OK;
}

/*







|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|







 







<







309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
...
361
362
363
364
365
366
367

368
369
370
371
372
373
374
**  (4)  step = $value   -- constraint exists
**  (8)  output in descending order
*/
static int seriesBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i, j;              /* Loop over constraints */
  int idxNum = 0;        /* The query plan bitmask */
  int unusableMask = 0;  /* Mask of unusable constraints */
  int nArg = 0;          /* Number of arguments that seriesFilter() expects */
  int aIdx[3];           /* Constraints on start, stop, and step */
  const struct sqlite3_index_constraint *pConstraint;

  /* This implementation assumes that the start, stop, and step columns
  ** are the last three columns in the virtual table. */
  assert( SERIES_COLUMN_STOP == SERIES_COLUMN_START+1 );
  assert( SERIES_COLUMN_STEP == SERIES_COLUMN_START+2 );
  aIdx[0] = aIdx[1] = aIdx[2] = -1;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    int iCol;    /* 0 for start, 1 for stop, 2 for step */
    int iMask;   /* bitmask for those column */
    if( pConstraint->iColumn<SERIES_COLUMN_START ) continue;
    iCol = pConstraint->iColumn - SERIES_COLUMN_START;
    iMask = 1 << iCol;
    if( pConstraint->usable==0 ){
      unusableMask |=  iMask;
      continue;
    }else if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      idxNum |= iMask;
      aIdx[iCol] = i;
    }
  }
  for(i=0; i<3; i++){
    if( (j = aIdx[i])>=0 ){
      pIdxInfo->aConstraintUsage[j].argvIndex = ++nArg;
      pIdxInfo->aConstraintUsage[j].omit = !SQLITE_SERIES_CONSTRAINT_VERIFY;
    }
  }
  if( (unusableMask & ~idxNum)!=0 ){
    /* The start, stop, and step columns are inputs.  Therefore if there
    ** are unusable constraints on any of start, stop, or step then
    ** this plan is unusable */
    return SQLITE_CONSTRAINT;
  }
  if( (idxNum & 3)==3 ){
    /* Both start= and stop= boundaries are available.  This is the 
    ** the preferred case */
    pIdxInfo->estimatedCost = (double)(2 - ((idxNum&4)!=0));
    pIdxInfo->estimatedRows = 1000;
    if( pIdxInfo->nOrderBy==1 ){
................................................................................
      if( pIdxInfo->aOrderBy[0].desc ) idxNum |= 8;
      pIdxInfo->orderByConsumed = 1;
    }
  }else{
    /* If either boundary is missing, we have to generate a huge span
    ** of numbers.  Make this case very expensive so that the query
    ** planner will work hard to avoid it. */

    pIdxInfo->estimatedRows = 2147483647;
  }
  pIdxInfo->idxNum = idxNum;
  return SQLITE_OK;
}

/*

Changes to src/where.c.

3136
3137
3138
3139
3140
3141
3142

3143
3144
3145
3146
3147
3148
3149
  rc = vtabBestIndex(pParse, pSrc->pTab, pIdxInfo);
  if( rc ){
    if( rc==SQLITE_CONSTRAINT ){
      /* If the xBestIndex method returns SQLITE_CONSTRAINT, that means
      ** that the particular combination of parameters provided is unusable.
      ** Make no entries in the loop table.
      */

      return SQLITE_OK;
    }
    return rc;
  }

  mxTerm = -1;
  assert( pNew->nLSlot>=nConstraint );







>







3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
  rc = vtabBestIndex(pParse, pSrc->pTab, pIdxInfo);
  if( rc ){
    if( rc==SQLITE_CONSTRAINT ){
      /* If the xBestIndex method returns SQLITE_CONSTRAINT, that means
      ** that the particular combination of parameters provided is unusable.
      ** Make no entries in the loop table.
      */
      WHERETRACE(0xffff, ("  ^^^^--- non-viable plan rejected!\n"));
      return SQLITE_OK;
    }
    return rc;
  }

  mxTerm = -1;
  assert( pNew->nLSlot>=nConstraint );