qe: fix pathological behaviour with many @uniques
#4179
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CodSpeed Performance ReportMerging #4179 will not alter performanceComparing Summary
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pimeys
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Aug 30, 2023
| #[connector_test] | ||
| async fn repro(runner: Runner) -> TestResult<()> { | ||
| let query = r#" | ||
| query { |
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@uniques
The quaint AST lets users keep track of unique index definitions in tables in order to generate `MERGE` statements in SQL Server. The SQL query connector diligently adds every unique index to the table definitions in the `AsTable` implementation for models. The concrete method used to add the indexes is `Table::add_unique_index()`. Its space complexity is `O(n!)` on the number of unique indexes on a model, which quickly leads to high memory usage, then hanging and out-of-memory errors. See the inline comment in the commit for more details on what happened exactly, and how this commit fixes the problem. The included regression test would consistently take multiple minutes, then OOM on a fast desktop machine with 32GB of RAM before the fix. closes prisma/prisma#20799
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Druue
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jkomyno
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The quaint AST lets users keep track of unique index definitions in
tables in order to generate
MERGEstatements in SQL Server.The SQL query connector diligently adds every unique index to the table
definitions in the
AsTableimplementation for models.The concrete method used to add the indexes is
Table::add_unique_index(). Its space complexity isO(n!)on thenumber of unique indexes on a model, which quickly leads to
high memory usage, then hanging and out-of-memory errors.
See the inline comment in the commit for more details on what happened
exactly, and how this commit fixes the problem. The included regression
test would consistently take multiple minutes, then OOM on a fast
desktop machine with 32GB of RAM before the fix.
closes prisma/prisma#20799