diff options
Diffstat (limited to 'src/include/access/relscan.h')
| -rw-r--r-- | src/include/access/relscan.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/include/access/relscan.h b/src/include/access/relscan.h index 6e6231971fd..356c7e6b048 100644 --- a/src/include/access/relscan.h +++ b/src/include/access/relscan.h @@ -20,6 +20,25 @@ #include "access/itup.h" #include "access/tupdesc.h" +/* + * Shared state for parallel heap scan. + * + * Each backend participating in a parallel heap scan has its own + * HeapScanDesc in backend-private memory, and those objects all contain + * a pointer to this structure. The information here must be sufficient + * to properly initialize each new HeapScanDesc as workers join the scan, + * and it must act as a font of block numbers for those workers. + */ +typedef struct ParallelHeapScanDescData +{ + Oid phs_relid; /* OID of relation to scan */ + bool phs_syncscan; /* report location to syncscan logic? */ + BlockNumber phs_nblocks; /* # blocks in relation at start of scan */ + slock_t phs_mutex; /* mutual exclusion for block number fields */ + BlockNumber phs_startblock; /* starting block number */ + BlockNumber phs_cblock; /* current block number */ + char phs_snapshot_data[FLEXIBLE_ARRAY_MEMBER]; +} ParallelHeapScanDescData; typedef struct HeapScanDescData { @@ -49,6 +68,7 @@ typedef struct HeapScanDescData BlockNumber rs_cblock; /* current block # in scan, if any */ Buffer rs_cbuf; /* current buffer in scan, if any */ /* NB: if rs_cbuf is not InvalidBuffer, we hold a pin on that buffer */ + ParallelHeapScanDesc rs_parallel; /* parallel scan information */ /* these fields only used in page-at-a-time mode and for bitmap scans */ int rs_cindex; /* current tuple's index in vistuples */ |