[SPARK-28495][SQL][FOLLOW-UP] Disallow conversions between timestamp and long in ASNI mode

[gengliangwang]

What changes were proposed in this pull request?

Disallow conversions between timestamp type and long type in table insertion with ANSI store assignment policy.

Why are the changes needed?

In the PR #25581, timestamp type is allowed to be converted to long type, since timestamp type is represented by long type internally, and both legacy mode and strict mode allows the conversion.

After reconsideration, I think we should disallow it. As per ANSI SQL section "4.4.2 Characteristics of numbers":

A number is assignable only to sites of numeric type.

In PostgreSQL, the conversion between timestamp and long is also disallowed.

Does this PR introduce any user-facing change?

Conversion between timestamp and long is disallowed in table insertion with ANSI store assignment policy.

How was this patch tested?

Unit test

[gengliangwang]

@cloud-fan @maropu Please help review this one.

[maropu]

The change looks reasonable to me. Just in case, I checked the pgSQL behaivour again;

postgres=# create table t (l bigint);
postgres=# insert into t values ('20190829 00:00:00'::timestamp);
2019-08-29 15:26:10.998 JST [4553] ERROR:  column "l" is of type bigint but expression is of type timestamp without time zone at character 23
2019-08-29 15:26:10.998 JST [4553] HINT:  You will need to rewrite or cast the expression.
2019-08-29 15:26:10.998 JST [4553] STATEMENT:  insert into t values ('20190829 00:00:00'::timestamp);
ERROR:  column "l" is of type bigint but expression is of type timestamp without time zone
LINE 1: insert into t values ('20190829 00:00:00'::timestamp);
                           

[maropu]

btw, we don't have any existing test for these cast case, right? (I just a bit worried about forgetting to add tests for the other cast cases in the ANSI mode...

[gengliangwang]

I think so. Let's wait for the test result.

[maropu]

yea, ok.

[SparkQA]

Test build #109899 has finished for PR 25615 at commit 75e3d96.

• This patch fails due to an unknown error code, -9.
• This patch merges cleanly.
• This patch adds no public classes.

[gengliangwang]

retest this please.

[SparkQA]

Test build #109901 has finished for PR 25615 at commit 75e3d96.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

thanks, merging to master!