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path: root/src/backend/jit/llvm/llvmjit_deform.c
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* Allow NOT NULL constraints to be added as NOT VALIDÁlvaro Herrera2025-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows them to be added without scanning the table, and validating them afterwards without holding access exclusive lock on the table after any violating rows have been deleted or fixed. Doing ALTER TABLE ... SET NOT NULL for a column that has an invalid not-null constraint validates that constraint. ALTER TABLE .. VALIDATE CONSTRAINT is also supported. There are various checks on whether an invalid constraint is allowed in a child table when the parent table has a valid constraint; this should match what we do for enforced/not enforced constraints. pg_attribute.attnotnull is now only an indicator for whether a not-null constraint exists for the column; whether it's valid or invalid must be queried in pg_constraint. Applications can continue to query pg_attribute.attnotnull as before, but now it's possible that NULL rows are present in the column even when that's set to true. For backend internal purposes, we cache the nullability status in CompactAttribute->attnullability that each tuple descriptor carries (replacing CompactAttribute.attnotnull, which was a mirror of Form_pg_attribute.attnotnull). During the initial tuple descriptor creation, based on the pg_attribute scan, we set this to UNRESTRICTED if pg_attribute.attnotnull is false, or to UNKNOWN if it's true; then we update the latter to VALID or INVALID depending on the pg_constraint scan. This flag is also copied when tupledescs are copied. Comparing tuple descs for equality must also compare the CompactAttribute.attnullability flag and return false in case of a mismatch. pg_dump deals with these constraints by storing the OIDs of invalid not-null constraints in a separate array, and running a query to obtain their properties. The regular table creation SQL omits them entirely. They are then dealt with in the same way as "separate" CHECK constraints, and dumped after the data has been loaded. Because no additional pg_dump infrastructure was required, we don't bump its version number. I decided not to bump catversion either, because the old catalog state works perfectly in the new world. (Trying to run with new catalog state and the old server version would likely run into issues, however.) System catalogs do not support invalid not-null constraints (because commit 14e87ffa5c54 didn't allow them to have pg_constraint rows anyway.) Author: Rushabh Lathia <rushabh.lathia@gmail.com> Author: Jian He <jian.universality@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Tested-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Discussion: https://postgr.es/m/CAGPqQf0KitkNack4F5CFkFi-9Dqvp29Ro=EpcWt=4_hs-Rt+bQ@mail.gmail.com
* Update copyright for 2025Bruce Momjian2025-01-01
| | | | Backpatch-through: 13
* Optimize alignment calculations in tuple form/deformDavid Rowley2024-12-21
| | | | | | | | | | | | | | | | | | | | | Here we convert CompactAttribute.attalign from a char, which is directly derived from pg_attribute.attalign into a uint8, which stores the number of bytes to align the column's value by in the tuple. This allows tuple deformation and tuple size calculations to move away from using the inefficient att_align_nominal() macro, which manually checks each TYPALIGN_* char to translate that into the alignment bytes for the given type. Effectively, this commit changes those to TYPEALIGN calls, which are branchless and only perform some simple arithmetic with some bit-twiddling. The removed branches were often mispredicted by CPUs, especially so in real-world tables which often contain a mishmash of different types with different alignment requirements. Author: David Rowley Reviewed-by: Andres Freund, Victor Yegorov Discussion: https://postgr.es/m/CAApHDvrBztXP3yx=NKNmo3xwFAFhEdyPnvrDg3=M0RhDs+4vYw@mail.gmail.com
* Introduce CompactAttribute array in TupleDesc, take 2David Rowley2024-12-20
| | | | | | | | | | | | | | | | | | | | | | | | The new compact_attrs array stores a few select fields from FormData_pg_attribute in a more compact way, using only 16 bytes per column instead of the 104 bytes that FormData_pg_attribute uses. Using CompactAttribute allows performance-critical operations such as tuple deformation to be performed without looking at the FormData_pg_attribute element in TupleDesc which means fewer cacheline accesses. For some workloads, tuple deformation can be the most CPU intensive part of processing the query. Some testing with 16 columns on a table where the first column is variable length showed around a 10% increase in transactions per second for an OLAP type query performing aggregation on the 16th column. However, in certain cases, the increases were much higher, up to ~25% on one AMD Zen4 machine. This also makes pg_attribute.attcacheoff redundant. A follow-on commit will remove it, thus shrinking the FormData_pg_attribute struct by 4 bytes. Author: David Rowley Reviewed-by: Andres Freund, Victor Yegorov Discussion: https://postgr.es/m/CAApHDvrBztXP3yx=NKNmo3xwFAFhEdyPnvrDg3=M0RhDs+4vYw@mail.gmail.com
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* jit: Support opaque pointers in LLVM 16.Thomas Munro2023-10-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove use of LLVMGetElementType() and provide the type of all pointers to LLVMBuildXXX() functions when emitting IR, as required by modern LLVM versions[1]. * For LLVM <= 14, we'll still use the old LLVMBuildXXX() functions. * For LLVM == 15, we'll continue to do the same, explicitly opting out of opaque pointer mode. * For LLVM >= 16, we'll use the new LLVMBuildXXX2() functions that take the extra type argument. The difference is hidden behind some new IR emitting wrapper functions l_load(), l_gep(), l_call() etc. The change is mostly mechanical, except that at each site the correct type had to be provided. In some places we needed to do some extra work to get functions types, including some new wrappers for C++ APIs that are not yet exposed by in LLVM's C API, and some new "example" functions in llvmjit_types.c because it's no longer possible to start from the function pointer type and ask for the function type. Back-patch to 12, because it's a little tricker in 11 and we agreed not to put the latest LLVM support into the upcoming final release of 11. [1] https://llvm.org/docs/OpaquePointers.html Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Ronan Dunklau <ronan.dunklau@aiven.io> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA%2BhUKGKNX_%3Df%2B1C4r06WETKTq0G4Z_7q4L4Fxn5WWpMycDj9Fw%40mail.gmail.com
* llvmjit: Use explicit LLVMContextRef for inliningDaniel Gustafsson2023-09-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When performing inlining LLVM unfortunately "leaks" types (the types survive and are usable, but a new round of inlining will recreate new structurally equivalent types). This accumulation will over time amount to a memory leak which for some queries can be large enough to trigger the OOM process killer. To avoid accumulation of types, all IR related data is stored in an LLVMContextRef which is dropped and recreated in order to release all types. Dropping and recreating incurs overhead, so it will be done only after 100 queries. This is a heuristic which might be revisited, but until we can get the size of the context from LLVM we are flying a bit blind. This issue has been reported several times, there may be more references to it in the archives on top of the threads linked below. Backpatching of this fix will be handled once it has matured in master for a bit. Reported-By: Justin Pryzby <pryzby@telsasoft.com> Reported-By: Kurt Roeckx <kurt@roeckx.be> Reported-By: Jaime Casanova <jcasanov@systemguards.com.ec> Reported-By: Lauri Laanmets <pcspets@gmail.com> Author: Andres Freund and Daniel Gustafsson Discussion: https://postgr.es/m/7acc8678-df5f-4923-9cf6-e843131ae89d@www.fastmail.com Discussion: https://postgr.es/m/20201218235607.GC30237@telsasoft.com Discussion: https://postgr.es/m/CAPH-tTxLf44s3CvUUtQpkDr1D8Hxqc2NGDzGXS1ODsfiJ6WSqA@mail.gmail.com
* Pre-beta mechanical code beautification.Tom Lane2023-05-19
| | | | | | | | | | | | | | | Run pgindent, pgperltidy, and reformat-dat-files. This set of diffs is a bit larger than typical. We've updated to pg_bsd_indent 2.1.2, which properly indents variable declarations that have multi-line initialization expressions (the continuation lines are now indented one tab stop). We've also updated to perltidy version 20230309 and changed some of its settings, which reduces its desire to add whitespace to lines to make assignments etc. line up. Going forward, that should make for fewer random-seeming changes to existing code. Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* Remove extraneous blank lines before block-closing bracesAlvaro Herrera2022-04-13
| | | | | | | | | These are useless and distracting. We wouldn't have written the code with them to begin with, so there's no reason to keep them. Author: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/20220411020336.GB26620@telsasoft.com Discussion: https://postgr.es/m/attachment/133167/0016-Extraneous-blank-lines.patch
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Introduce macros for typalign and typstorage constants.Tom Lane2020-03-04
| | | | | | | | | | | | | | | | | | | | | Our usual practice for "poor man's enum" catalog columns is to define macros for the possible values and use those, not literal constants, in C code. But for some reason lost in the mists of time, this was never done for typalign/attalign or typstorage/attstorage. It's never too late to make it better though, so let's do that. The reason I got interested in this right now is the need to duplicate some uses of the TYPSTORAGE constants in an upcoming ALTER TYPE patch. But in general, this sort of change aids greppability and readability, so it's a good idea even without any specific motivation. I may have missed a few places that could be converted, and it's even more likely that pending patches will re-introduce some hard-coded references. But that's not fatal --- there's no expectation that we'd actually change any of these values. We can clean up stragglers over time. Discussion: https://postgr.es/m/16457.1583189537@sss.pgh.pa.us
* jit: Reference expression step functions via llvmjit_types.Andres Freund2020-02-06
| | | | | | | | | | | | | | The main benefit of doing so is that this allows llvm to ensure that types match - previously that'd only be detected by a crash within the called function. There were a number of cases where we passed a superfluous parameter... To avoid needing to add all the functions to llvmjit.{c,h}, instead get them from the llvm module for llvmjit_types.c. Also use that for the functions from llvmjit_types already in llvmjit.h. Author: Soumyadeep Chakraborty and Andres Freund Discussion: https://postgr.es/m/CADwEdooww3wZv-sXSfatzFRwMuwa186LyTwkBfwEW6NjtooBPA@mail.gmail.com
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Fix typos.Amit Kapila2019-05-26
| | | | | | | Reported-by: Alexander Lakhin Author: Alexander Lakhin Reviewed-by: Amit Kapila and Tom Lane Discussion: https://postgr.es/m/7208de98-add8-8537-91c0-f8b089e2928c@gmail.com
* Improve comment spelling and style in llvmjit_deform.c.Andres Freund2019-04-30
| | | | | | | Author: Justin Pryzby Discussion: https://postgr.es/m/20190408141828.GE10080@telsasoft.com https://postgr.es/m/20181127184133.GM10913@telsasoft.com
* Improve code inferring length of bitmap for JITed tuple deforming.Andres Freund2019-04-30
| | | | | | | | | | | | | | | | | | | | | | While discussing comment improvements (see next commit) by Justin Pryzby, Tom complained about a few details of the logic to infer the length of the NULL bitmap when building the JITed tuple deforming function. That bitmap allows to avoid checking the tuple header's natts, a check which often causes a pipeline stall Improvements: a) As long as missing columns aren't taken into account, we can continue to infer the length of the NULL bitmap from NOT NULL columns following it. Previously we stopped at the first missing column. It's unlikely to matter much in practice, but the alternative would have been to document why we stop. b) For robustness reasons it seems better to also check against attisdropped - RemoveAttributeById() sets attnotnull to false, but an additional check is trivial. c) Improve related comments Discussion: https://postgr.es/m/20637.1555957068@sss.pgh.pa.us Backpatch: -
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Fix jit compilation bug on wide tables.Andres Freund2018-11-27
| | | | | | | | | | | | | | | | | | | | The function generated to perform JIT compiled tuple deforming failed when HeapTupleHeader's t_hoff was bigger than a signed int8. I'd failed to realize that LLVM's getelementptr would treat an int8 index argument as signed, rather than unsigned. That means that a hoff larger than 127 would result in a negative offset being applied. Fix that by widening the index to 32bit. Add a testcase with a wide table. Don't drop it, as it seems useful to verify other tools deal properly with wide tables. Thanks to Justin Pryzby for both reporting a bug and then reducing it to a reproducible testcase! Reported-By: Justin Pryzby Author: Andres Freund Discussion: https://postgr.es/m/20181115223959.GB10913@telsasoft.com Backpatch: 11, just as jit compilation was
* Make TupleTableSlots extensible, finish split of existing slot type.Andres Freund2018-11-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit completes the work prepared in 1a0586de36, splitting the old TupleTableSlot implementation (which could store buffer, heap, minimal and virtual slots) into four different slot types. As described in the aforementioned commit, this is done with the goal of making tuple table slots extensible, to allow for pluggable table access methods. To achieve runtime extensibility for TupleTableSlots, operations on slots that can differ between types of slots are performed using the TupleTableSlotOps struct provided at slot creation time. That includes information from the size of TupleTableSlot struct to be allocated, initialization, deforming etc. See the struct's definition for more detailed information about callbacks TupleTableSlotOps. I decided to rename TTSOpsBufferTuple to TTSOpsBufferHeapTuple and ExecCopySlotTuple to ExecCopySlotHeapTuple, as that seems more consistent with other naming introduced in recent patches. There's plenty optimization potential in the slot implementation, but according to benchmarking the state after this commit has similar performance characteristics to before this set of changes, which seems sufficient. There's a few changes in execReplication.c that currently need to poke through the slot abstraction, that'll be repaired once the pluggable storage patchset provides the necessary infrastructure. Author: Andres Freund and Ashutosh Bapat, with changes by Amit Khandekar Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
* Don't generate tuple deforming functions for virtual slots.Andres Freund2018-11-15
| | | | | | | | | | Virtual tuple table slots never need tuple deforming. Therefore, if we know at expression compilation time, that a certain slot will always be virtual, there's no need to create a tuple deforming routine for it. Author: Andres Freund Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
* Move TupleTableSlots boolean member into one flag variable.Andres Freund2018-10-15
| | | | | | | | | | | | | | | There's several reasons for this change: 1) It reduces the total size of TupleTableSlot / reduces alignment padding, making the commonly accessed members fit into a single cacheline (but we currently do not force proper alignment, so that's not yet guaranteed to be helpful) 2) Combining the booleans into a flag allows to combine read/writes from memory. 3) With the upcoming slot abstraction changes, it allows to have core and extended flags, in a memory efficient way. Author: Ashutosh Bapat and Andres Freund Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
* Change TupleTableSlot->tts_nvalid to type AttrNumber.Andres Freund2018-09-25
| | | | | | | | | | Previously it was an int / 4 bytes. The maximum number of attributes in a tuple is restricted by the maximum value Var->varattno, which is an AttrNumber/int16. Hence use the same data type for TupleTableSlot->tts_nvalid. Author: Ashutosh Bapat Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
* Quick adaption of JIT tuple deforming to the fast default patch.Andres Freund2018-03-27
| | | | | | | | | | | Instead using memset to set tts_isnull, call the new slot_getmissingattrs(). Also fix a bug (= instead of >=) in the code generation. Normally = is correct, but when repeatedly deforming fields not in a tuple (e.g. deform up to natts + 1 and then natts + 2) >= is needed. Discussion: https://postgr.es/m/20180328010053.i2qvsuuusst4lgmc@alap3.anarazel.de
* JIT tuple deforming in LLVM JIT provider.Andres Freund2018-03-26
Performing JIT compilation for deforming gains performance benefits over unJITed deforming from compile-time knowledge of the tuple descriptor. Fixed column widths, NOT NULLness, etc can be taken advantage of. Right now the JITed deforming is only used when deforming tuples as part of expression evaluation (and obviously only if the descriptor is known). It's likely to be beneficial in other cases, too. By default tuple deforming is JITed whenever an expression is JIT compiled. There's a separate boolean GUC controlling it, but that's expected to be primarily useful for development and benchmarking. Docs will follow in a later commit containing docs for the whole JIT feature. Author: Andres Freund Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de