planner: fix a sporadic panic due to the PR #7684 when using the prepared plan cache #7956
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Hi contributor, thanks for your PR. This patch needs to be approved by someone of admins. They should reply with "/ok-to-test" to accept this PR for running test automatically. |
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PTAL @jackysp |
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/run-all-tests |
zz-jason
added
contribution
planner/core/optimizer.go
Outdated
| @@ -66,6 +66,7 @@ type logicalOptRule interface { | |||
| func BuildLogicalPlan(ctx sessionctx.Context, node ast.Node, is infoschema.InfoSchema) (Plan, error) { | |||
| ctx.GetSessionVars().PlanID = 0 | |||
| ctx.GetSessionVars().PlanColumnID = 0 | |||
| ctx.GetSessionVars().StmtCtx.UseCache = false | |||
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StmtCtx.UseCache is set in: https://github.com/pingcap/tidb/blob/master/executor/prepared.go#L155
Then the function BuildLogicalPlan() is called. Maybe it's better to set StmtCtx.UseCache to false before the function BuildLogicalPlan() call: https://github.com/pingcap/tidb/blob/master/executor/prepared.go#L162
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If we can ensure calling BuildLogicalPlan() at prepared.go#L162 only, setting the variable at the location as you said is good. Otherwise, setting the variable in BuildLogicalPlan() might be a good choice in order to prevent from a potential risk because StmtCtx.UseCache should be false in the call paths of BuildLogicalPlan().
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Yes, we can ensure. Function BuildLogicalPlan() is only used in the test code and the prepare statements:
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You can get the similar result by:
find . -name "*.go" | xargs grep --color -n "\<BuildLogicalPlan\>"
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@zz-jason Thank you for the comment. I've updated the PR. |
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/run-all-tests |
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/run-all-tests |
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@dbjoa I will add a integeration test in internal test repo to cover this question. |
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/run-all-tests tidb-test=pr/637 |
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It's a simple test case: public void testPrepareCacheIssue8065() throws Exception {
createTable("test_prepare1", "(a int)");
createTable("test_prepare2", "(a int, b int)");
try {
try (PreparedStatement pStmt = this.conn.prepareStatement("select * from test_prepare1 where a = ?")) {
pStmt.setInt(1, 1);
this.rs = pStmt.executeQuery();
while(this.rs.next()) {}
}
try (PreparedStatement pStmt = this.conn.prepareStatement("select * from test_prepare2 where a = ? and b = ?")) {
pStmt.setInt(1, 1);
pStmt.setInt(2, 2);
this.rs = pStmt.executeQuery();
while(this.rs.next()) {}
}
} finally {
if (this.rs != null) {
this.rs.close();
}
this.rs = null;
}
}and 9643cde make plan-cache enable in CI env |
…pared plan cache main: default enable prepare plan cache in test env
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PTAL @lysu |
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/run-all-tests |
…he prepared plan cache (pingcap#7956)
What problem does this PR solve?
fixes #8065
Fix the panics are occurred sporadically after merging the PR #7684 when using the prepared plan cache.
What is changed and how it works?
Initialize UseCache of the statement context in BuildLogicalPlan
Check List
Tests
Code changes
Side effects
Related changes