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https://issues.apache.org/jira/browse/IGNITE-26404?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Aleksandr Chesnokov updated IGNITE-26404:
-----------------------------------------
Description:
{{H2QueryInfo#planWithoutScanCount}} does not consider all cases:
1) It deletes only the first occurrence of the {{scanCount}} field, but there
can be several occurrences (e.g. in {{{}UNION{}}})
2) Sometimes {{scanCount}} is located inside {{/++ ... ++/}} comments, not in
{{/* ... */}}
As a result, it generates local plans for perfStat that differ only by
{{{}scanCount{}}}, which makes {{perfStat}} heavier
An example is given below.
Before:
{noformat}
SELECT
u.id,
u.name
FROM users u
WHERE u.active = true
/* scanCount: 1 */
UNION ALL
SELECT
c.id,
c.contact_name
FROM customers c
WHERE c.status = 'VIP';
/* scanCount: 3 */
{noformat}
After:
{noformat}
SELECT
u.id,
u.name
FROM users u
WHERE u.active = true
UNION ALL
SELECT
c.id,
c.contact_name
FROM customers c
WHERE c.status = 'VIP'
ORDER BY name;
{noformat}
was:
{{H2QueryInfo#planWithoutScanCount}} does not consider all cases:
1) It deletes only the first occurrence of the {{scanCount}} field, but there
can be several occurrences (e.g. in {{{}UNION{}}})
2) Sometimes {{scanCount}} is located inside {{/++ ... ++/}} comments, not in
{{/* ... */}}
As a result, it generates local plans for perfStat that differ only by
{{{}scanCount{}}}, which makes {{perfStat}} heavier
An example is given below.
Before:
{noformat}
SELECT /* scanCount: 1 */
u.id,
u.name
FROM users u
WHERE u.active = true
UNION ALL
SELECT /* scanCount: 3 */
c.id,
c.contact_name
FROM customers c
WHERE c.status = 'VIP'
ORDER BY name;
{noformat}
After:
{noformat}
SELECT
u.id,
u.name
FROM users u
WHERE u.active = true
UNION ALL
SELECT
c.id,
c.contact_name
FROM customers c
WHERE c.status = 'VIP'
ORDER BY name;
{noformat}
> H2QueryInfo#planWithoutScanCount does not consider all cases
> ------------------------------------------------------------
>
> Key: IGNITE-26404
> URL: https://issues.apache.org/jira/browse/IGNITE-26404
> Project: Ignite
> Issue Type: Bug
> Reporter: Aleksandr Chesnokov
> Assignee: Aleksandr Chesnokov
> Priority: Major
> Labels: ise
> Time Spent: 10m
> Remaining Estimate: 0h
>
> {{H2QueryInfo#planWithoutScanCount}} does not consider all cases:
> 1) It deletes only the first occurrence of the {{scanCount}} field, but there
> can be several occurrences (e.g. in {{{}UNION{}}})
> 2) Sometimes {{scanCount}} is located inside {{/++ ... ++/}} comments, not in
> {{/* ... */}}
> As a result, it generates local plans for perfStat that differ only by
> {{{}scanCount{}}}, which makes {{perfStat}} heavier
> An example is given below.
> Before:
>
> {noformat}
> SELECT
> u.id,
> u.name
> FROM users u
> WHERE u.active = true
> /* scanCount: 1 */
> UNION ALL
> SELECT
> c.id,
> c.contact_name
> FROM customers c
> WHERE c.status = 'VIP';
> /* scanCount: 3 */
> {noformat}
> After:
> {noformat}
> SELECT
> u.id,
> u.name
> FROM users u
> WHERE u.active = true
> UNION ALL
> SELECT
> c.id,
> c.contact_name
> FROM customers c
> WHERE c.status = 'VIP'
> ORDER BY name;
> {noformat}
>
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