Hi,
I've pushed the first two parts (backfill of empty ranges for serial
builds, allowing parallelism) after a bit more cleanup, adding a simple
pageinspect test to 0001, improving comments and some minor adjustments.
I ended up removing the protections against BlockNumber overflows, and
moved them into a separate WIP patch. I still think we should probably
reconsider the position that we don't need to worry about issues so
close to the 32TB boundary, but it seemed rather weird to fix only the
new bits and leave the existing issues in place.
I'm attaching that as a WIP patch, but I don't know if/when I'll get
back to this.
Thanks for the reviews/reworks/ideas!
--
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
From cf53c109c73cfa9264df71763e9ec5712f1c1f7f Mon Sep 17 00:00:00 2001
From: Tomas Vondra <to...@2ndquadrant.com>
Date: Thu, 7 Dec 2023 15:07:04 +0100
Subject: [PATCH] WIP: Prevent overflows for BRIN page ranges
Introduces remove brin_next_range that checks if blkno overflows, and
instead sets it to InvalidBlockNumber.
---
src/backend/access/brin/brin.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index 23f081389b2..1952142d050 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -227,6 +227,7 @@ static bool add_values_to_range(Relation idxRel, BrinDesc *bdesc,
static bool check_null_keys(BrinValues *bval, ScanKey *nullkeys, int nnullkeys);
static void brin_fill_empty_ranges(BrinBuildState *state,
BlockNumber prevRange, BlockNumber maxRange);
+static BlockNumber brin_next_range(BrinBuildState *state, BlockNumber blkno);
/* parallel index builds */
static void _brin_begin_parallel(BrinBuildState *buildstate, Relation heap, Relation index,
@@ -2935,7 +2936,7 @@ brin_fill_empty_ranges(BrinBuildState *state,
* If we already summarized some ranges, we need to start with the next
* one. Otherwise start from the first range of the table.
*/
- blkno = (prevRange == InvalidBlockNumber) ? 0 : (prevRange + state->bs_pagesPerRange);
+ blkno = (prevRange == InvalidBlockNumber) ? 0 : brin_next_range(state, prevRange);
/* Generate empty ranges until we hit the next non-empty range. */
while (blkno < nextRange)
@@ -2948,6 +2949,18 @@ brin_fill_empty_ranges(BrinBuildState *state,
blkno, state->bs_emptyTuple, state->bs_emptyTupleLen);
/* try next page range */
- blkno += state->bs_pagesPerRange;
+ blkno = brin_next_range(state, blkno);
}
}
+
+static BlockNumber
+brin_next_range(BrinBuildState *state, BlockNumber blkno)
+{
+ BlockNumber ret = (blkno + state->bs_pagesPerRange);
+
+ /* overflow */
+ if (ret < blkno)
+ ret = InvalidBlockNumber;
+
+ return ret;
+}
--
2.41.0
