diff options
Diffstat (limited to 'src/include/executor')
| -rw-r--r-- | src/include/executor/hashjoin.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/include/executor/hashjoin.h b/src/include/executor/hashjoin.h index 3beae403ce6..c9e61dfa39c 100644 --- a/src/include/executor/hashjoin.h +++ b/src/include/executor/hashjoin.h @@ -102,6 +102,25 @@ typedef struct HashSkewBucket #define SKEW_WORK_MEM_PERCENT 2 #define SKEW_MIN_OUTER_FRACTION 0.01 +/* + * To reduce palloc overhead, the HashJoinTuples for the current batch are + * packed in 32kB buffers instead of pallocing each tuple individually. + */ +typedef struct HashMemoryChunkData +{ + int ntuples; /* number of tuples stored in this chunk */ + size_t maxlen; /* size of the buffer holding the tuples */ + size_t used; /* number of buffer bytes already used */ + + struct HashMemoryChunkData *next; /* pointer to the next chunk (linked list) */ + + char data[1]; /* buffer allocated at the end */ +} HashMemoryChunkData; + +typedef struct HashMemoryChunkData *HashMemoryChunk; + +#define HASH_CHUNK_SIZE (32 * 1024L) +#define HASH_CHUNK_THRESHOLD (HASH_CHUNK_SIZE / 4) typedef struct HashJoinTableData { @@ -157,6 +176,9 @@ typedef struct HashJoinTableData MemoryContext hashCxt; /* context for whole-hash-join storage */ MemoryContext batchCxt; /* context for this-batch-only storage */ + + /* used for dense allocation of tuples (into linked chunks) */ + HashMemoryChunk chunks; /* one list for the whole batch */ } HashJoinTableData; #endif /* HASHJOIN_H */ |