diff options
Diffstat (limited to 'src/backend/access')
| -rw-r--r-- | src/backend/access/tablesample/bernoulli.c | 15 | ||||
| -rw-r--r-- | src/backend/access/tablesample/tablesample.c | 9 |
2 files changed, 12 insertions, 12 deletions
diff --git a/src/backend/access/tablesample/bernoulli.c b/src/backend/access/tablesample/bernoulli.c index 563a9168f0f..0a539008221 100644 --- a/src/backend/access/tablesample/bernoulli.c +++ b/src/backend/access/tablesample/bernoulli.c @@ -80,8 +80,7 @@ Datum tsm_bernoulli_nextblock(PG_FUNCTION_ARGS) { TableSampleDesc *tsdesc = (TableSampleDesc *) PG_GETARG_POINTER(0); - BernoulliSamplerData *sampler = - (BernoulliSamplerData *) tsdesc->tsmdata; + BernoulliSamplerData *sampler = (BernoulliSamplerData *) tsdesc->tsmdata; /* * Bernoulli sampling scans all blocks on the table and supports syncscan @@ -117,10 +116,10 @@ tsm_bernoulli_nextblock(PG_FUNCTION_ARGS) * tuples have same probability of being returned the visible and invisible * tuples will be returned in same ratio as they have in the actual table. * This means that there is no skew towards either visible or invisible tuples - * and the number returned visible tuples to from the executor node is the - * fraction of visible tuples which was specified in input. + * and the number of visible tuples returned from the executor node should + * match the fraction of visible tuples which was specified by user. * - * This is faster than doing the coinflip in the examinetuple because we don't + * This is faster than doing the coinflip in examinetuple because we don't * have to do visibility checks on uninteresting tuples. * * If we reach end of the block return InvalidOffsetNumber which tells @@ -131,8 +130,7 @@ tsm_bernoulli_nexttuple(PG_FUNCTION_ARGS) { TableSampleDesc *tsdesc = (TableSampleDesc *) PG_GETARG_POINTER(0); OffsetNumber maxoffset = PG_GETARG_UINT16(2); - BernoulliSamplerData *sampler = - (BernoulliSamplerData *) tsdesc->tsmdata; + BernoulliSamplerData *sampler = (BernoulliSamplerData *) tsdesc->tsmdata; OffsetNumber tupoffset = sampler->lt; float4 probability = sampler->probability; @@ -185,8 +183,7 @@ Datum tsm_bernoulli_reset(PG_FUNCTION_ARGS) { TableSampleDesc *tsdesc = (TableSampleDesc *) PG_GETARG_POINTER(0); - BernoulliSamplerData *sampler = - (BernoulliSamplerData *) tsdesc->tsmdata; + BernoulliSamplerData *sampler = (BernoulliSamplerData *) tsdesc->tsmdata; sampler->blockno = InvalidBlockNumber; sampler->lt = InvalidOffsetNumber; diff --git a/src/backend/access/tablesample/tablesample.c b/src/backend/access/tablesample/tablesample.c index 3398d02f854..44a24340f6b 100644 --- a/src/backend/access/tablesample/tablesample.c +++ b/src/backend/access/tablesample/tablesample.c @@ -78,9 +78,12 @@ tablesample_init(SampleScanState *scanstate, TableSampleClause *tablesample) fcinfo.argnull[0] = false; /* - * Second arg for init function is always REPEATABLE When - * tablesample->repeatable is NULL then REPEATABLE clause was not - * specified. When specified, the expression cannot evaluate to NULL. + * Second arg for init function is always REPEATABLE. + * + * If tablesample->repeatable is NULL then REPEATABLE clause was not + * specified, and we insert a random value as default. + * + * When specified, the expression cannot evaluate to NULL. */ if (tablesample->repeatable) { |