diff options
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/executor/hashjoin.h | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/include/executor/hashjoin.h b/src/include/executor/hashjoin.h index d8c82d4e7c..be83500b9d 100644 --- a/src/include/executor/hashjoin.h +++ b/src/include/executor/hashjoin.h @@ -117,7 +117,7 @@ typedef struct HashSkewBucket typedef struct HashMemoryChunkData { int ntuples; /* number of tuples stored in this chunk */ - size_t maxlen; /* size of the buffer holding the tuples */ + size_t maxlen; /* size of the chunk's tuple buffer */ size_t used; /* number of buffer bytes already used */ /* pointer to the next chunk (linked list) */ @@ -127,13 +127,19 @@ typedef struct HashMemoryChunkData dsa_pointer shared; } next; - char data[FLEXIBLE_ARRAY_MEMBER]; /* buffer allocated at the end */ + /* + * The chunk's tuple buffer starts after the HashMemoryChunkData struct, + * at offset HASH_CHUNK_HEADER_SIZE (which must be maxaligned). Note that + * that offset is not included in "maxlen" or "used". + */ } HashMemoryChunkData; typedef struct HashMemoryChunkData *HashMemoryChunk; #define HASH_CHUNK_SIZE (32 * 1024L) -#define HASH_CHUNK_HEADER_SIZE (offsetof(HashMemoryChunkData, data)) +#define HASH_CHUNK_HEADER_SIZE MAXALIGN(sizeof(HashMemoryChunkData)) +#define HASH_CHUNK_DATA(hc) (((char *) (hc)) + HASH_CHUNK_HEADER_SIZE) +/* tuples exceeding HASH_CHUNK_THRESHOLD bytes are put in their own chunk */ #define HASH_CHUNK_THRESHOLD (HASH_CHUNK_SIZE / 4) /* |