Thread: Limit GIST_MAX_SPLIT_PAGES to XLR_MAX_BLOCK_ID
Gin code respects the XLR_MAX_BLOCK_ID when calling XLogEnsureRecordSpace(). But it appears that the Gist code does not try to limit its block-id consumption to XLR_MAX_BLOCK_ID.
The GIST_MAX_SPLIT_PAGES is hard-coded at 75, but XLogEnsureRecordSpace() would reject a request of more than 32 (XLR_MAX_BLOCK_ID).
The attached patch redefines GIST_MAX_SPLIT_PAGES so that in case of a split, gistplacetopage() now throws an error when the block-ids needed exceed 32.
I have used Min(75, XLR_MAX_BLOCK_ID) as the macro expansion, but I believe it can be set to plain XLR_MAX_BLOCK_ID.
Attachment
(adding Heikki, since that macro was touched by his commit 04e298b8)
Does my previous description of the problem make sense, or am I fretting over something that's a non-issue.
Best regards,
On Sun, Sep 20, 2015 at 7:03 PM, Gurjeet Singh <gurjeet@singh.im> wrote:
Gin code respects the XLR_MAX_BLOCK_ID when calling XLogEnsureRecordSpace(). But it appears that the Gist code does not try to limit its block-id consumption to XLR_MAX_BLOCK_ID.The GIST_MAX_SPLIT_PAGES is hard-coded at 75, but XLogEnsureRecordSpace() would reject a request of more than 32 (XLR_MAX_BLOCK_ID).The attached patch redefines GIST_MAX_SPLIT_PAGES so that in case of a split, gistplacetopage() now throws an error when the block-ids needed exceed 32.I have used Min(75, XLR_MAX_BLOCK_ID) as the macro expansion, but I believe it can be set to plain XLR_MAX_BLOCK_ID.
Gurjeet Singh http://gurjeet.singh.im/