Add support for scanning multiple spans for a single index. #2293
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| @@ -54,7 +54,6 @@ func moveMoney(db *sql.DB) { | |||
| log.Fatal(err) | |||
| } | |||
| startTime := time.Now() | |||
| // Query is very slow and will be fixed by https://github.com/cockroachdb/cockroach/issues/2140 | |||
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The query is usually no longer very slow, but I still sometimes see log messages like:
I0828 15:07:06.299984 34037 examples/sql_bank/main.go:61 SELECT id, balance FROM accounts WHERE id IN (130, 204) took 3.059484793s
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LGTM with test coverage of more interesting index constraints |
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| @@ -92,6 +101,13 @@ EXPLAIN (DEBUG) SELECT * FROM t WHERE a = 1 AND b > 'b' | |||
| 0 /t/primary/1/'c' NULL true | |||
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| query ITTB | |||
| EXPLAIN (DEBUG) SELECT * FROM t WHERE a > 1 AND b > 'ba' | |||
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can you make this a > 2? currently this is just a table scan, i think
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It's an index scan in the sense that it constructed a key using the constraint a > 1. I can see this from debug info at log.V(2). If I changed this to a > 2 no keys would be scanned.
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Add support for scanning multiple spans for a single index.
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Index selection now creates multiple independent spans of the index that
must be scanned. Multiple spans are created for expressions like "a
IN (1, 2, 3)" and "a = 1 OR a = 2 or a = 3" (these are equivalent).
Fixes #2140.
See #2142.