SQL to reproduce:
```
SELECT * FROM table WHERE where FROM_UNIXTIME(d_datekey,'%Y-%m-%d %H:%i:%s') != '1970-08-20 00:11:43';
org.apache.doris.common.AnalysisException: errCode = 2, detailMessage = Unexpected exception: Illegal pattern character 'i'
at org.apache.doris.qe.StmtExecutor.analyze(StmtExecutor.java:584) ~[palo-fe.jar:3.4.0]
at org.apache.doris.qe.StmtExecutor.execute(StmtExecutor.java:345) ~[palo-fe.jar:3.4.0]
at org.apache.doris.qe.StmtExecutor.execute(StmtExecutor.java:318) ~[palo-fe.jar:3.4.0]
at org.apache.doris.qe.ConnectProcessor.handleQuery(ConnectProcessor.java:221) ~[palo-fe.jar:3.4.0]
at org.apache.doris.qe.ConnectProcessor.dispatch(ConnectProcessor.java:361) ~[palo-fe.jar:3.4.0]
at org.apache.doris.qe.ConnectProcessor.processOnce(ConnectProcessor.java:562) ~[palo-fe.jar:3.4.0]
at org.apache.doris.mysql.nio.ReadListener.lambda$handleEvent$0(ReadListener.java:50) ~[palo-fe.jar:3.4.0]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
at java.lang.Thread.run(Thread.java:835) [?:?]
```
Describe the overview of changes.
Just support:
yyyy-MM-dd HH:mm:ss
yyyy-MM-dd
yyyyMMdd
1. en: add convert_tz.md
2. en: fix curdate.md, the fix is to modify the title
3. en: add curtime.md
4. en: fix str_to_date.md, the fix is to modify the title
5. zh-CN: fix convert_tz.md, the fix is to modify the description
6. zh-CN: fix curdate.md, the fix is to modify the title
#4619
Add time_round functions that provides `time_floor` & `time_ceil` at each time unit.
Fix two related bugs.
- #4618
- Fix `struct TimeInterval` to use `int64_t` instead of `int32_t`, in case when the second diff overflow
Main CL:
1. Copy the code from BE to implement the `str_to_date()` function in FE.
2. `str_to_date("2020-08-08", "%Y-%m-%d %H:%i:%s")` will return `2020-08-08 00:00:00` instead of `2020-08-08`.
Fix: #3946
CL:
1. Add prepare phase for `from_unixtime()`, `date_format()` and `convert_tz()` functions, to handle the format string once for all.
2. Find the cctz timezone when init `runtime state`, so that don't need to find timezone for each rows.
3. Add constant rewrite rule for `utc_timestamp()`
4. Add doc for `to_date()`
5. Comment out the `push_handler_test`, it can not run in DEBUG mode, will be fixed later.
6. Remove `timezone_db.h/cpp` and add `timezone_utils.h/cpp`
The performance shows bellow:
11,000,000 rows
SQL1: `select count(from_unixtime(k1)) from tbl1;`
Before: 8.85s
After: 2.85s
SQL2: `select count(from_unixtime(k1, '%Y-%m-%d %H:%i:%s')) from tbl1 limit 1;`
Before: 10.73s
After: 4.85s
The date string format seems still slow, we may need a further enhancement about it.
