RFC: Always treat the argument of to_timestamp(<number>) as microsecs

[andylokandy]

to_timestamp in Snowflake and Databend treats its argument as seconds, milliseconds, or micros depending on the number scale (detailed spec). Because the user has to control the behavior with the input value, it may not be error-prone enough, especially when converting a column of values. Therefore, I propose to fix the argument to microsecs.

[andylokandy]

cc @BohuTANG @sundy-li @Xuanwo

[sundy-li]

Agree.

Related to issue: #5698 cc @wubx

[sundy-li]

But is there a better way to create a timestamp from number without place too much trailing zeros?

to_timestamp(1665556629000000)

1665556629000000 is tooooo long to use.

[sundy-li]

Oh. I found the parser supported it.

MySQL [(none)]> select to_timestamp(1665556629e6);
+--------------------------------+
| to_timestamp(1665556629000000) |
+--------------------------------+
| 2022-10-12 06:37:09.000000     |
+--------------------------------+
1 row in set (0.024 sec)

[andylokandy]

in snowflake, to_timestamp could accept an extra argument scale for that purpose