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https://issues.apache.org/jira/browse/TRAFODION-3277?focusedWorklogId=201068&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-201068
]
ASF GitHub Bot logged work on TRAFODION-3277:
---------------------------------------------
Author: ASF GitHub Bot
Created on: 20/Feb/19 03:47
Start Date: 20/Feb/19 03:47
Worklog Time Spent: 10m
Work Description: liuyu000 commented on pull request #1799:
[TRAFODION-3277] Add *OVERLAPS predicate* in Trafodion SQL Reference Manual
URL: https://github.com/apache/trafodion/pull/1799#discussion_r258324614
##########
File path: docs/sql_reference/src/asciidoc/_chapters/sql_language_elements.adoc
##########
@@ -3694,6 +3694,393 @@ evaluates to null:
(first_name, salary) IS NULL
```
+<<<
+[[overlaps_predicate]]
+=== OVERLAPS Predicate
+
+The OVERLAPS predicate evaluates whether two date-time periods overlap each
other. The date-time period is a pair of date-time expressions.
+
+```
+(start 1, end 1) OVERLAPS (start 2, end 2)
+```
+
+[[syntax_description_of_overlaps]]
+==== Syntax Description of OVERLAPS
+
+* `_start 1, start 2_`
+
++
+Specifies the beginning of a date-time period, which can be a DATE, TIME or
TIMESTAMP value.
+
++
+NOTE: `_start 1, start 2_` cannot be NULL.
+
+
+* `_end 1, end 2_`
++
+Specifies the end of a date-time period, which can be a DATE, TIME, TIMESTAMP
or INTERVAL value.
+
++
+NOTE: `_end 1, end 2_` cannot be NULL.
+
++
+The INTERVAL value advances or decrements date-time period.
+
++
+*Example*
+
++
+These two date-time periods overlap since TIMESTAMP '2019-11-02 01:00:00' is
less than one hour before TIMESTAMP '2019-11-02 02:00:01'.
+
++
+```
+SELECT 'Technical Writer' FROM DUAL
+WHERE
+(TIMESTAMP '2019-11-02 02:00:01', INTERVAL -'1' HOUR)
+OVERLAPS
+(TIMESTAMP '2019-11-02 01:00:00', INTERVAL '2' HOUR);
+
+(EXPR)
+----------------
+Technical Writer
+
+--- 1 row(s) selected.
+```
+
+[[considerations_for_overlaps]]
+==== Considerations for OVERLAPS
+
+* If two date-time periods are not instantaneous, they overlap when they share
a common period, that is, they must have one-second overlap for TIME/TIMESTAMP
or one-day overlap for DATE/TIMESTAMP.
+
++
+TIP: S1-E1 stands for `_(start 1, end 1)_`, S2-E2 stands for `_(start 2, end
2)_`, and so forth.
Review comment:
@DaveBirdsall Thanks Dave, your comment has been incorporated. I'll merge
this PR and update website.
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Issue Time Tracking
-------------------
Worklog Id: (was: 201068)
Time Spent: 1h (was: 50m)
> Add *OVERLAPS predicate* in Trafodion SQL Reference Manual
> ----------------------------------------------------------
>
> Key: TRAFODION-3277
> URL: https://issues.apache.org/jira/browse/TRAFODION-3277
> Project: Apache Trafodion
> Issue Type: Documentation
> Reporter: Liu Yu
> Assignee: Liu Yu
> Priority: Major
> Time Spent: 1h
> Remaining Estimate: 0h
>
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