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Code Issues

More optimizer enhancements.

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When an equal-node and other nodes (geq, leq, between...) are available for an index retrieval, then use the equal node always instead of the others.
This commit is contained in:
arnobrinkman 2003-02-15 01:35:19 +00:00
parent c531ac3659
commit afc3d38954
1 changed files with 42 additions and 30 deletions
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72
src/jrd/opt.cpp
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@ -5603,7 +5603,7 @@ static SSHORT match_index(TDBB tdbb,
/* match the field to an index, if possible, and save the value to be matched
as either the lower or upper bound for retrieval, or both */
for (i = 0, ptr = opt->opt_rpt; i < idx->idx_count; i++, ptr++)
for (i = 0, ptr = opt->opt_rpt; i < idx->idx_count; i++, ptr++) {
if
#ifdef EXPRESSION_INDICES
(idx->idx_expression ||
@ -5614,39 +5614,51 @@ static SSHORT match_index(TDBB tdbb,
#endif
{
++count;
/* AB: If we have already an exact match don't
override it with worser matches, but increment the
count so that the node will be marked as matched! */
if (ptr->opt_match && ptr->opt_match->nod_type == nod_eql) {
break;
}
switch (boolean->nod_type) {
case nod_between:
if (!forward ||
!computable(opt->opt_csb, boolean->nod_arg[2], stream,
TRUE)) return 0;
ptr->opt_lower = value;
ptr->opt_upper = boolean->nod_arg[2];
ptr->opt_match = boolean;
break;
case nod_eql:
ptr->opt_lower = ptr->opt_upper = value;
ptr->opt_match = boolean;
break;
case nod_gtr:
case nod_geq:
if (forward)
case nod_between:
if (!forward || !computable(opt->opt_csb,
boolean->nod_arg[2], stream, TRUE)) {
return 0;
}
ptr->opt_lower = value;
else
ptr->opt_upper = value;
ptr->opt_match = boolean;
break;
case nod_lss:
case nod_leq:
if (forward)
ptr->opt_upper = value;
else
ptr->opt_lower = value;
ptr->opt_match = boolean;
break;
default: /* Shut up compiler warnings */
break;
ptr->opt_upper = boolean->nod_arg[2];
ptr->opt_match = boolean;
break;
case nod_eql:
ptr->opt_lower = ptr->opt_upper = value;
ptr->opt_match = boolean;
break;
case nod_gtr:
case nod_geq:
if (forward) {
ptr->opt_lower = value;
}
else {
ptr->opt_upper = value;
}
ptr->opt_match = boolean;
break;
case nod_lss:
case nod_leq:
if (forward) {
ptr->opt_upper = value;
}
else {
ptr->opt_lower = value;
}
ptr->opt_match = boolean;
break;
default: /* Shut up compiler warnings */
break;
}
}
}
return count;
}