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path: root/src/backend/access/gist/gistbuildbuffers.c
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* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Improve hash_create's API for selecting simple-binary-key hash functions.Tom Lane2014-12-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, if you wanted anything besides C-string hash keys, you had to specify a custom hashing function to hash_create(). Nearly all such callers were specifying tag_hash or oid_hash; which is tedious, and rather error-prone, since a caller could easily miss the opportunity to optimize by using hash_uint32 when appropriate. Replace this with a design whereby callers using simple binary-data keys just specify HASH_BLOBS and don't need to mess with specific support functions. hash_create() itself will take care of optimizing when the key size is four bytes. This nets out saving a few hundred bytes of code space, and offers a measurable performance improvement in tidbitmap.c (which was not exploiting the opportunity to use hash_uint32 for its 4-byte keys). There might be some wins elsewhere too, I didn't analyze closely. In future we could look into offering a similar optimized hashing function for 8-byte keys. Under this design that could be done in a centralized and machine-independent fashion, whereas getting it right for keys of platform-dependent sizes would've been notationally painful before. For the moment, the old way still works fine, so as not to break source code compatibility for loadable modules. Eventually we might want to remove tag_hash and friends from the exported API altogether, since there's no real need for them to be explicitly referenced from outside dynahash.c. Teodor Sigaev and Tom Lane
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Improve coding of gistchoose and gistRelocateBuildBuffersOnSplit.Tom Lane2012-08-30
| | | | | | | | This is mostly cosmetic, but it does eliminate a speculative portability issue. The previous coding ignored the fact that sum_grow could easily overflow (in fact, it could be summing multiple IEEE float infinities). On a platform where that didn't guarantee to produce a positive result, the code would misbehave. In any case, it was less than readable.
* Fix logic bug in gistchoose and gistRelocateBuildBuffersOnSplit.Robert Haas2012-08-30
| | | | | | | | | | | | Every time the best-tuple-found-so-far changes, we need to reset all the penalty values in which_grow[] to the penalties for the new best tuple. The old code failed to do this, resulting in inferior index quality. The original patch from Alexander Korotkov was just two lines; I took the liberty of fleshing that out by adding a bunch of comments that I hope will make this logic easier for others to understand than it was for me.
* Run pgindent on 9.2 source tree in preparation for first 9.3Bruce Momjian2012-06-10
| | | | commit-fest.
* Change the way parent pages are tracked during buffered GiST build.Heikki Linnakangas2012-05-30
| | | | | | | | | | | | | | | | | | We used to mimic the way a stack is constructed when descending the tree during normal GiST inserts, but that was quite complicated during a buffered build. It was also wrong: in GiST, the left-to-right relationships on different levels might not match each other, so that when you know the parent of a child page, you won't necessarily find the parent of the page to the right of the child page by following the rightlinks at the parent level. This sometimes led to "could not re-find parent" errors while building a GiST index. We now use a simple hash table to track the parent of every internal page. Whenever a page is split, and downlinks are moved from one page to another, we update the hash table accordingly. This is also better for performance than the old method, as we never need to move right to re-find the parent page, which could take a significant amount of time for buffers that were created much earlier in the index build.
* Delete the temporary file used in buffered GiST build, after the build.Heikki Linnakangas2012-05-30
| | | | | | There were two bugs here: We forgot to call gistFreeBuildBuffers() function at the end of build, and we passed interXact == true to BufFileCreateTemp, so the file wasn't automatically cleaned up at end-of-transaction either.
* Fix bug in gistRelocateBuildBuffersOnSplit().Heikki Linnakangas2012-05-18
| | | | | | | | | | | | | | | | | | | When we create a temporary copy of the old node buffer, in stack, we mustn't leak that into any of the long-lived data structures. Before this patch, when we called gistPopItupFromNodeBuffer(), it got added to the array of "loaded buffers". After gistRelocateBuildBuffersOnSplit() exits, the pointer added to the loaded buffers array points to garbage. Often that goes unnotied, because when we go through the array of loaded buffers to unload them, buffers with a NULL pageBuffer are ignored, which can often happen by accident even if the pointer points to garbage. This patch fixes that by marking the temporary copy in stack explicitly as temporary, and refrain from adding buffers marked as temporary to the array of loaded buffers. While we're at it, initialize nodeBuffer->pageBlocknum to InvalidBlockNumber and improve comments a bit. This isn't strictly necessary, but makes debugging easier.
* When a GiST page is split during index build, it might not have a buffer.Heikki Linnakangas2012-03-02
| | | | | | | | | | | | | Previously it was thought that it's impossible as the code stands, because insertions create buffers as tuples are cascaded downwards, and index split also creaters buffers eagerly for all halves. But the example from Jay Levitt demonstrates that it can happen, when the root page is split. It's in fact OK if the buffer doesn't exist, so we just need to remove the sanity check. In fact, we've been discussing the possibility of destroying empty buffers to conserve memory, which would render the sanity check completely useless anyway. Fix by Alexander Korotkov
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Buffering GiST index build algorithm.Heikki Linnakangas2011-09-08
When building a GiST index that doesn't fit in cache, buffers are attached to some internal nodes in the index. This speeds up the build by avoiding random I/O that would otherwise be needed to traverse all the way down the tree to the find right leaf page for tuple. Alexander Korotkov