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Indexed MIN/MAX aggregates produce three index reads instead of the expected one indexed read [CORE1389] #1807

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firebird-automations opened this issue Jul 31, 2007 · 6 comments
Closed

Indexed MIN/MAX aggregates produce three index reads instead of the expected one indexed read [CORE1389] #1807

firebird-automations opened this issue Jul 31, 2007 · 6 comments
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@dyemanov
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affect-version: 1.0.3 affect-version: 1.5.2 affect-version: 1.5.3 affect-version: 1.5.4 affect-version: 2.0.0 affect-version: 2.0.1 affect-version: 2.1 Alpha 1 affect-version: 2.1 Beta 1 component: engine fix-version: 2.1 Beta 2 priority: minor qa: done successfully type: improvement

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Submitted by: @dyemanov

One could expect that SELECT MIN(COL) FROM TAB is completely equivalent to SELECT FIRST 1 COL FROM TAB ORDER BY 1 ASC and that both should perform a single record read (provided that an ASC index on COL exists and that COL is non-nullable). However, the former query requires three indexed reads while the latter one behaves as expected and require just one indexed read.

Commits: cc0b9f9
@firebird-automations
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Modified by: @dyemanov

status: Open [ 1 ] => Resolved [ 5 ]

resolution: Fixed [ 1 ]

Fix Version: 2.1 Beta 2 [ 10190 ]

@firebird-automations
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Modified by: @pcisar

Workflow: jira [ 12721 ] => Firebird [ 15066 ]

@firebird-automations
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Modified by: @pcisar

status: Resolved [ 5 ] => Closed [ 6 ]

@firebird-automations
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Modified by: @pavel-zotov

QA Status: No test

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Modified by: @pavel-zotov

status: Closed [ 6 ] => Closed [ 6 ]

QA Status: No test => Done with caveats

Test Details: Ticked issues can be verified only by using TRACE log parsing.
Gathering of MON$ data seems bad way: some values are added to the number
of indexed reads so they are GREATER than expected (i.e. more than 1).

See inside .fbt file for more details (including source SQL of previous test prototype for this ticket and its result).

@firebird-automations
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Modified by: @pavel-zotov

status: Closed [ 6 ] => Closed [ 6 ]

QA Status: Done with caveats => Done successfully

Test Details: Ticked issues can be verified only by using TRACE log parsing.
Gathering of MON$ data seems bad way: some values are added to the number
of indexed reads so they are GREATER than expected (i.e. more than 1).

See inside .fbt file for more details (including source SQL of previous test prototype for this ticket and its result).

=>

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affect-version: 1.0.3 affect-version: 1.5.2 affect-version: 1.5.3 affect-version: 1.5.4 affect-version: 2.0.0 affect-version: 2.0.1 affect-version: 2.1 Alpha 1 affect-version: 2.1 Beta 1 component: engine fix-version: 2.1 Beta 2 priority: minor qa: done successfully type: improvement
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