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Overview
Comment:Avoid invoking the whereLoopAddOr() routine in the query planner if there are no OR operators in the WHERE clause, thus speeding up query planning slightly.
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SHA3-256:292724ffc4bfca435fff309383d488ffdbe1e314e5eb26da21cf2f621b64bce5
User & Date: drh 2018-06-09 00:09:58
References
2018-06-11
01:30
Always initialize the WhereClause.hasOr field that was added by check-in [292724ffc4]. Error detected by OSSFuzz. check-in: 9faf4171 user: drh tags: trunk
Context
2018-06-09
01:12
Compute the bitmask of indexed columns for each index once when the Index objecct is constructed, instead of recomputing it every time it is needed. check-in: d735872e user: drh tags: trunk
00:09
Avoid invoking the whereLoopAddOr() routine in the query planner if there are no OR operators in the WHERE clause, thus speeding up query planning slightly. check-in: 292724ff user: drh tags: trunk
2018-06-08
23:23
When the query planner has the opportunity to use an IN operater constraint on a term of an index other than the left-most term, use the estimated number of elements on the right-hand side of the IN operator to determine if makes sense to use the IN operator with index lookups, or to just do a scan over the range of the table identified by the index terms to the left. Only do this if sqlite_stat1 measurements are available as otherwise the performance estimates will not be accurate enough to discern the best plan. Bias the decision slightly in favor of using index lookups on each element of the IN operator. check-in: 2cbbabdf user: drh tags: trunk
Changes
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Changes to src/where.c.

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      }
      rc = whereLoopAddVirtual(pBuilder, mPrereq, mUnusable);
    }else
#endif /* SQLITE_OMIT_VIRTUALTABLE */
    {
      rc = whereLoopAddBtree(pBuilder, mPrereq);
    }
    if( rc==SQLITE_OK ){
      rc = whereLoopAddOr(pBuilder, mPrereq, mUnusable);
    }
    mPrior |= pNew->maskSelf;
    if( rc || db->mallocFailed ) break;
  }

  whereLoopClear(db, pNew);







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      }
      rc = whereLoopAddVirtual(pBuilder, mPrereq, mUnusable);
    }else
#endif /* SQLITE_OMIT_VIRTUALTABLE */
    {
      rc = whereLoopAddBtree(pBuilder, mPrereq);
    }
    if( rc==SQLITE_OK && pBuilder->pWC->hasOr ){
      rc = whereLoopAddOr(pBuilder, mPrereq, mUnusable);
    }
    mPrior |= pNew->maskSelf;
    if( rc || db->mallocFailed ) break;
  }

  whereLoopClear(db, pNew);

Changes to src/whereInt.h.

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** the subclauses "(b AND c)" and "(d AND e)".  The pOuter field of the
** subclauses points to the WhereClause object for the whole clause.
*/
struct WhereClause {
  WhereInfo *pWInfo;       /* WHERE clause processing context */
  WhereClause *pOuter;     /* Outer conjunction */
  u8 op;                   /* Split operator.  TK_AND or TK_OR */

  int nTerm;               /* Number of terms */
  int nSlot;               /* Number of entries in a[] */
  WhereTerm *a;            /* Each a[] describes a term of the WHERE cluase */
#if defined(SQLITE_SMALL_STACK)
  WhereTerm aStatic[1];    /* Initial static space for a[] */
#else
  WhereTerm aStatic[8];    /* Initial static space for a[] */







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** the subclauses "(b AND c)" and "(d AND e)".  The pOuter field of the
** subclauses points to the WhereClause object for the whole clause.
*/
struct WhereClause {
  WhereInfo *pWInfo;       /* WHERE clause processing context */
  WhereClause *pOuter;     /* Outer conjunction */
  u8 op;                   /* Split operator.  TK_AND or TK_OR */
  u8 hasOr;                /* True if any a[].eOperator is WO_OR */
  int nTerm;               /* Number of terms */
  int nSlot;               /* Number of entries in a[] */
  WhereTerm *a;            /* Each a[] describes a term of the WHERE cluase */
#if defined(SQLITE_SMALL_STACK)
  WhereTerm aStatic[1];    /* Initial static space for a[] */
#else
  WhereTerm aStatic[8];    /* Initial static space for a[] */

Changes to src/whereexpr.c.

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  }

  /*
  ** Record the set of tables that satisfy case 3.  The set might be
  ** empty.
  */
  pOrInfo->indexable = indexable;

  pTerm->eOperator = indexable==0 ? 0 : WO_OR;





  /* For a two-way OR, attempt to implementation case 2.
  */
  if( indexable && pOrWc->nTerm==2 ){
    int iOne = 0;
    WhereTerm *pOne;
    while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){







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  }

  /*
  ** Record the set of tables that satisfy case 3.  The set might be
  ** empty.
  */
  pOrInfo->indexable = indexable;
  if( indexable ){
    pTerm->eOperator = WO_OR;
    pWC->hasOr = 1;
  }else{
    pTerm->eOperator = WO_OR;
  }

  /* For a two-way OR, attempt to implementation case 2.
  */
  if( indexable && pOrWc->nTerm==2 ){
    int iOne = 0;
    WhereTerm *pOne;
    while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){