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Add support for optimising nested loop a bit (primary key lookup).

moonshot/custom-path
Nils Dijk 2020-01-20 19:07:00 +01:00
parent 2937d4edc9
commit ffa33b096a
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GPG Key ID: CA1177EF9434F241
1 changed files with 27 additions and 19 deletions
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46
src/backend/distributed/planner/path_based_planner.c
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@ -27,7 +27,7 @@ static Index VarnoFromFirstTargetEntry(List *tlist);
static Query * GetQueryFromPath(PlannerInfo *root, Path *path, List *tlist, List *clauses);
static List * ShardIntervalListToRelationShardList(List *shardIntervalList);
static Path * OptimizeJoinPath(Path *originalPath);
static bool CanOptimizeHashPath(HashPath *hpath);
static bool CanOptimizeJoinPath(JoinPath *jpath);
static bool IsDistributedUnion(Path *path);
typedef struct DistributedUnionPath
@ -207,17 +207,17 @@ PathBasedPlannerRelationHook(PlannerInfo *root,
}
static bool
CanOptimizeHashPath(HashPath *hpath)
CanOptimizeJoinPath(JoinPath *jpath)
{
if (!(IsDistributedUnion(hpath->jpath.innerjoinpath) &&
IsDistributedUnion(hpath->jpath.outerjoinpath)))
if (!(IsDistributedUnion(jpath->innerjoinpath) &&
IsDistributedUnion(jpath->outerjoinpath)))
{
/* can only optimize joins when both inner and outer are a distributed union */
return false;
}
DistributedUnionPath *innerDU = (DistributedUnionPath *) hpath->jpath.innerjoinpath;
DistributedUnionPath *outerDU = (DistributedUnionPath *) hpath->jpath.outerjoinpath;
DistributedUnionPath *innerDU = (DistributedUnionPath *) jpath->innerjoinpath;
DistributedUnionPath *outerDU = (DistributedUnionPath *) jpath->outerjoinpath;
if (innerDU->colocationId != outerDU->colocationId)
{
@ -233,26 +233,33 @@ CanOptimizeHashPath(HashPath *hpath)
static Path *
OptimizeJoinPath(Path *originalPath)
{
if (IsA(originalPath, HashPath))
switch (originalPath->pathtype)
{
HashPath *hpath = castNode(HashPath, originalPath);
if (CanOptimizeHashPath(hpath))
case T_NestLoop:
case T_HashJoin:
{
/* we can only optimize the Distributed union if the colocationId's are the same, taking any would suffice */
uint32 colocationId = ((DistributedUnionPath *) hpath->jpath.innerjoinpath)->colocationId;
JoinPath *jpath = (JoinPath *) originalPath;
if (CanOptimizeJoinPath(jpath))
{
/* we can only optimize the Distributed union if the colocationId's are the same, taking any would suffice */
uint32 colocationId = ((DistributedUnionPath *) jpath->innerjoinpath)->colocationId;
hpath->jpath.innerjoinpath = ((DistributedUnionPath *)hpath->jpath.innerjoinpath)->worker_path;
hpath->jpath.outerjoinpath = ((DistributedUnionPath *)hpath->jpath.outerjoinpath)->worker_path;
jpath->innerjoinpath = ((DistributedUnionPath *) jpath->innerjoinpath)->worker_path;
jpath->outerjoinpath = ((DistributedUnionPath *) jpath->outerjoinpath)->worker_path;
/* TODO update costs of hashjoin, very naife removal of DU cost for now */
hpath->jpath.path.startup_cost -= 2000; /* remove the double dist union cost */
hpath->jpath.path.total_cost -= 2000; /* remove the double dist union cost */
/* TODO update costs of hashjoin, very naife removal of DU cost for now */
jpath->path.startup_cost -= 2000; /* remove the double dist union cost */
jpath->path.total_cost -= 2000; /* remove the double dist union cost */
return (Path *) WrapTableAccessWithDistributedUnion((Path *) hpath, colocationId);
return (Path *) WrapTableAccessWithDistributedUnion((Path *) jpath, colocationId);
}
}
default:
{
return originalPath;
}
}
return originalPath;
}
@ -372,6 +379,7 @@ ApplyPathToQuery(PlannerInfo *root, Query *query, Path *path, PathQueryInfo *inf
break;
}
case T_NestLoop:
case T_HashJoin:
{
JoinPath *jpath = (JoinPath *) path;