HIVE-29059: SHOW CREATE TABLE ignores all strings after tab character for VIEWs

[cyanzheng2926]

… for views

What changes were proposed in this pull request?

Addresses the issue for HIVE-29059 when a view is created with actual tabs, the SHOW CREATE TABLE output would truncate all strings after the tab.

Why are the changes needed?

SHOW CREATE TABLE of a view's create comment containing tab characters should have the same behaviour as COMMENTs when running SHOW CREATE TABLE on a normal table, which should display tab as \t instead of truncating all contents after it.

Does this PR introduce any user-facing change?

Yes.
When tab is present in the create view statement, running SHOW CREATE TABLE would truncate the output after the tab. e.g.:
CREATE TABLE t1 (val1 string, val2 string);
CREATE VIEW v1 AS SELECT * FROM t1 WHERE val1 = 'a'; -- There is a tab present at val1= 'a';
SHOW CREATE TABLE v1;
-- This would originally output below:
+----------------------------------------------------+
| createtab_stmt |
+----------------------------------------------------+
| CREATE VIEW v1 AS SELECT t1.val1, t1.val2 FROM default.t1 WHERE t1.val1 |
+----------------------------------------------------+

After the fix, the tab is replaced by explicit \t which is similar to the behaviour of how SHOW CREATE TABLE deals with tabs for COMMENT. e.g.:
+----------------------------------------------------+
| createtab_stmt |
+----------------------------------------------------+
| CREATE VIEW v1 AS SELECT t1.val1, t1.val2 FROM default.t1 WHERE t1.val1\t= 'a' |
+----------------------------------------------------+

How was this patch tested?

Created show_create_table_tab_view.q which contains testing tab for several cases
Tests run on TestMiniLlapCliDriver under minillap.query.files

[Copilot]

Pull request overview

Fixes HIVE-29059 where SHOW CREATE TABLE for VIEWs can truncate output after literal tab characters by escaping tab characters in the rendered VIEW DDL, and adds a qtest covering several tab-containing VIEW definitions.

Changes:

• Escape literal tab characters (\t) in SHOW CREATE TABLE output for VIEWs.
• Add a new clientpositive qtest that creates/views with tabs in whitespace and string literals and verifies \t escaping.
• Add the corresponding LLAP expected output file for the new qtest.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/create/show/ShowCreateTableOperation.java	Escapes tab characters in the generated CREATE VIEW statement before writing results.
ql/src/test/queries/clientpositive/show_create_table_tab_view.q	New qtest query file exercising tab characters in VIEW definitions and literals.
ql/src/test/results/clientpositive/llap/show_create_table_tab_view.q.out	New LLAP golden output validating \t escaping and non-view behavior.

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[ayushtkn]

minor comments, rest looks good

[cyanzheng2926]

Hi @ayushtkn thanks again for the review :) I've addressed all the suggested changes.

[ayushtkn]

Minor comment, rest LGTM

[ayushtkn]

I don't think this is required, you can add a normal test, adding to these files is required for specific cases when u want LLAP or Tez, else by default it goes to normal CLI driver, drop this and move the q.out

[cyanzheng2926]

Understood, thanks!

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud