wzhfy opened a new pull request #35440:
URL: https://github.com/apache/spark/pull/35440
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### What changes were proposed in this pull request?
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Currently timestamp column's stats (min/max) are stored in UTC in metastore,
and when desc its min/max column stats, they are also shown in UTC.
As a result, for users not in UTC, the column stats (shown to users) are not
consistent with the actual value, which causes confusion.
### Why are the changes needed?
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To make column stats and column value consistent when shown to users.
### Does this PR introduce _any_ user-facing change?
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As an example:
```
spark-sql> create table tab_ts_master (ts timestamp) using parquet;
spark-sql> insert into tab_ts_master values make_timestamp(2022, 1, 1, 0, 0,
1.123456), make_timestamp(2022, 1, 3, 0, 0, 2.987654);
spark-sql> select * from tab_ts_master;
2022-01-01 00:00:01.123456
2022-01-03 00:00:02.987654
spark-sql> set spark.sql.session.timeZone;
spark.sql.session.timeZone Asia/Shanghai
spark-sql> analyze table tab_ts_master compute statistics for all columns;
```
Before this change:
```
spark-sql> desc formatted tab_ts_master ts;
col_name ts
data_type timestamp
comment NULL
min 2021-12-31 16:00:01.123456
max 2022-01-02 16:00:02.987654
num_nulls 0
distinct_count 2
avg_col_len 8
max_col_len 8
histogram NULL
```
The min/max column stats are inconsistent with what the user sees in the
column values.
After this change:
```
spark-sql> desc formatted tab_ts ts;
col_name ts
data_type timestamp
comment NULL
min 2022-01-01 00:00:01.123456
max 2022-01-03 00:00:02.987654
num_nulls 0
distinct_count 2
avg_col_len 8
max_col_len 8
histogram NULL
```
### How was this patch tested?
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Added new unit tests.
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