[IMPALA-3231] renaming table discards column statistics

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: impala 2.3
• Component/s: Catalog
• Labels: CBO DDL ramp-up statistics
• Environment: CDH 5.5.2
• Target Version: Product Backlog
• Assignee: Unassigned
• Reporter: Ruslan Dautkhanov
• Created: 22/Mar/16 18:50
• Updated: 18/Aug/17 20:43
• Resolved: 18/Aug/17 20:43

Description

Renaming table discards column statistics.
Some of the tables we have collecting stats takes an hour, so it would be great to preserve stats if we have to rename a table.

Test case:

create table test_col_stats_a
as
select 'aa' union all select 'bb' ;

show column stats test_col_stats_a;

compute stats test_col_stats_a;

show column stats test_col_stats_a;

alter table test_col_stats_a rename to test_col_stats_b;

show column stats test_col_stats_b;

Issue Links

• duplicates: IMPALA-4767 Table stats are removed after any ALTER TABLE in Impala