diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2015-05-18 18:34:37 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2015-05-18 18:34:37 -0400 |
| commit | 4db485e75b9672126963ae4052b50f473b30a097 (patch) | |
| tree | c82504c5924d228715402e03b3dfbb2a72eed0bb /src/include/utils/sampling.h | |
| parent | f5916bb7b53f8a77c95c00c5b287659958891178 (diff) | |
Put back a backwards-compatible version of sampling support functions.
Commit 83e176ec18d2a91dbea1d0d1bd94c38dc47cd77c removed the longstanding
support functions for block sampling without any consideration of the
impact this would have on third-party FDWs. The new API is not notably
more functional for FDWs than the old, so forcing them to change doesn't
seem like a good thing. We can provide the old API as a wrapper (more
or less) around the new one for a minimal amount of extra code.
Diffstat (limited to 'src/include/utils/sampling.h')
| -rw-r--r-- | src/include/utils/sampling.h | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/src/include/utils/sampling.h b/src/include/utils/sampling.h index 4ac208dc364..476bb002346 100644 --- a/src/include/utils/sampling.h +++ b/src/include/utils/sampling.h @@ -3,7 +3,7 @@ * sampling.h * definitions for sampling functions * - * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group + * Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * src/include/utils/sampling.h @@ -13,7 +13,8 @@ #ifndef SAMPLING_H #define SAMPLING_H -#include "storage/bufmgr.h" +#include "storage/block.h" /* for typedef BlockNumber */ + /* Random generator for sampling code */ typedef unsigned short SamplerRandomState[3]; @@ -23,6 +24,7 @@ extern void sampler_random_init_state(long seed, extern double sampler_random_fract(SamplerRandomState randstate); /* Block sampling methods */ + /* Data structure for Algorithm S from Knuth 3.4.2 */ typedef struct { @@ -40,7 +42,8 @@ extern void BlockSampler_Init(BlockSampler bs, BlockNumber nblocks, extern bool BlockSampler_HasMore(BlockSampler bs); extern BlockNumber BlockSampler_Next(BlockSampler bs); -/* Reservoid sampling methods */ +/* Reservoir sampling methods */ + typedef struct { double W; @@ -52,4 +55,11 @@ typedef ReservoirStateData *ReservoirState; extern void reservoir_init_selection_state(ReservoirState rs, int n); extern double reservoir_get_next_S(ReservoirState rs, double t, int n); +/* Old API, still in use by assorted FDWs */ +/* For backwards compatibility, these declarations are duplicated in vacuum.h */ + +extern double anl_random_fract(void); +extern double anl_init_selection_state(int n); +extern double anl_get_next_S(double t, int n, double *stateptr); + #endif /* SAMPLING_H */ |