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Merge pull request #1369 from citusdata/featurefix/better-range-pruning 

Improve / Fix range pruning
pull/1323/head
Andres Freund 2017-04-28 17:45:58 -07:00 committed by GitHub
parent e029724227 90b211267d
commit 0cc9171984
1 changed files with 132 additions and 81 deletions
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87
src/backend/distributed/planner/shard_pruning.c
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@ -186,6 +186,9 @@ static List * PruneWithBoundaries(DistTableCacheEntry *cacheEntry,
static List * ExhaustivePrune(DistTableCacheEntry *cacheEntry,
ClauseWalkerContext *context,
PruningInstance *prune);
static bool ExhaustivePruneOne(ShardInterval *curInterval,
ClauseWalkerContext *context,
PruningInstance *prune);
static int UpperShardBoundary(Datum partitionColumnValue,
ShardInterval **shardIntervalCache,
int shardCount, FunctionCallInfoData *compareFunction,
@ -894,15 +897,27 @@ PruneOne(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *context,
}
/*
* If previous pruning method yielded a single shard, we could also
* attempt range based pruning to exclude it further. But that seems
* rarely useful in practice, and thus likely a waste of runtime and code
* complexity.
* If previous pruning method yielded a single shard, and the table is not
* hash partitioned, attempt range based pruning to exclude it further.
*
* That's particularly important in particular for subquery pushdown,
* where it's very common to have a user specified equality restriction,
* and a range based restriction for shard boundaries, added by the
* subquery machinery.
*/
if (shardInterval)
{
if (context->partitionMethod != DISTRIBUTE_BY_HASH &&
ExhaustivePruneOne(shardInterval, context, prune))
{
return NIL;
}
else
{
/* no chance to prune further, return */
return list_make1(shardInterval);
}
}
/*
* Should never get here for hashing, we've filtered down to either zero
@ -1157,11 +1172,21 @@ PruneWithBoundaries(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *contex
hasLowerBound = true;
}
if (prune->greaterConsts)
{
/*
* Use the more restrictive one, if both greater and greaterEqual
* constraints are specified.
*/
if (!hasLowerBound ||
PerformValueCompare(compareFunctionCall,
prune->greaterConsts->constvalue,
lowerBound) >= 0)
{
lowerBound = prune->greaterConsts->constvalue;
lowerBoundInclusive = false;
hasLowerBound = true;
}
}
if (prune->lessEqualConsts)
{
upperBound = prune->lessEqualConsts->constvalue;
@ -1169,11 +1194,21 @@ PruneWithBoundaries(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *contex
hasUpperBound = true;
}
if (prune->lessConsts)
{
/*
* Use the more restrictive one, if both less and lessEqual
* constraints are specified.
*/
if (!hasUpperBound ||
PerformValueCompare(compareFunctionCall,
prune->lessConsts->constvalue,
upperBound) <= 0)
{
upperBound = prune->lessConsts->constvalue;
upperBoundInclusive = false;
hasUpperBound = true;
}
}
Assert(hasLowerBound || hasUpperBound);
@ -1232,21 +1267,40 @@ ExhaustivePrune(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *context,
PruningInstance *prune)
{
List *remainingShardList = NIL;
FunctionCallInfo compareFunctionCall = &context->compareIntervalFunctionCall;
int shardCount = cacheEntry->shardIntervalArrayLength;
ShardInterval **sortedShardIntervalArray = cacheEntry->sortedShardIntervalArray;
int curIdx = 0;
for (curIdx = 0; curIdx < shardCount; curIdx++)
{
Datum compareWith = 0;
ShardInterval *curInterval = sortedShardIntervalArray[curIdx];
if (!ExhaustivePruneOne(curInterval, context, prune))
{
remainingShardList = lappend(remainingShardList, curInterval);
}
}
return remainingShardList;
}
/*
* ExhaustivePruneOne returns true if curInterval is pruned away, false
* otherwise.
*/
static bool
ExhaustivePruneOne(ShardInterval *curInterval,
ClauseWalkerContext *context,
PruningInstance *prune)
{
FunctionCallInfo compareFunctionCall = &context->compareIntervalFunctionCall;
Datum compareWith = 0;
/* NULL boundaries can't be compared to */
if (!curInterval->minValueExists || !curInterval->maxValueExists)
{
remainingShardList = lappend(remainingShardList, curInterval);
continue;
return false;
}
if (prune->equalConsts)
@ -1257,14 +1311,14 @@ ExhaustivePrune(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *context,
compareWith,
curInterval->minValue) < 0)
{
continue;
return true;
}
if (PerformValueCompare(compareFunctionCall,
compareWith,
curInterval->maxValue) > 0)
{
continue;
return true;
}
}
if (prune->greaterEqualConsts)
@ -1275,7 +1329,7 @@ ExhaustivePrune(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *context,
curInterval->maxValue,
compareWith) < 0)
{
continue;
return true;
}
}
if (prune->greaterConsts)
@ -1286,7 +1340,7 @@ ExhaustivePrune(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *context,
curInterval->maxValue,
compareWith) <= 0)
{
continue;
return true;
}
}
if (prune->lessEqualConsts)
@ -1297,7 +1351,7 @@ ExhaustivePrune(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *context,
curInterval->minValue,
compareWith) > 0)
{
continue;
return true;
}
}
if (prune->lessConsts)
@ -1308,12 +1362,9 @@ ExhaustivePrune(DistTableCacheEntry *cacheEntry, ClauseWalkerContext *context,
curInterval->minValue,
compareWith) >= 0)
{
continue;
return true;
}
}
remainingShardList = lappend(remainingShardList, curInterval);
}
return remainingShardList;
return false;
}