On 2024-07-05 12:59, Fujii Masao wrote:
On 2024/07/04 12:05, torikoshia wrote:
I'm going to update it after discussing the option format as described
below.
Thanks!
I agree that it's possible to use only REJECT_LIMIT without ON_ERROR.
I also think it's easy to understand that REJECT_LIMIT=0 is
ON_ERROR=stop.
However, expressing REJECT_LIMIT='infinity' needs some definition like
"setting REJECT_LIMIT to -1 means 'infinity'", doesn't it? If so, I
think this might not so intuitive.
How about allowing REJECT_LIMIT to accept the keywords "infinity",
"unlimited",
or "all" in addition to a number? This way, users can specify one of
these
keywords instead of -1 to ignore all errors. The server code would then
internally set the REJECT_LIMIT to -1 or another appropriate value when
these keywords are used, but users wouldn't need to worry about this
detail.
Agreed.
If we choose "all" as the keyword, renaming the option to IGNORE_ERRORS
might be more intuitive and easier to understand than REJECT_LIMIT.
I feel that 'infinite' and 'unlimited' are unfamiliar values for
PostgreSQL parameters, so 'all' might be better and IGNORE_ERRORS would
be a better parameter name as your suggestion.
Also, since it seems Snowflake and Redshift have both options
equivalent to REJECT_LIMIT and ON_ERROR, having both of them in
PostgreSQL COPY might not be surprising:
- Snowflake's ON_ERROR accepts "CONTINUE | SKIP_FILE | SKIP_FILE_num |
'SKIP_FILE_num%' | ABORT_STATEMENT"[1]
- Redshift has MAXERROR and IGNOREALLERRORS options[2]
Ok, so here's a summary of the options and their behaviors:
To ignore all errors and continue to the end:
- Snowflake: ON_ERROR=CONTINUE
- Redshift: IGNOREALLERRORS
- Postgres (with your patch): ON_ERROR=ignore
- Postgres (with my idea): IGNORE_ERRORS=all
To fail as soon as an error is found:
- Snowflake: ON_ERROR=ABORT_STATEMENT (default) / SKIP_FILE
- Redshift: MAXERROR=0 (default)
- Postgres (with your patch): ON_ERROR=stop (default)
- Postgres (with my idea): IGNORE_ERRORS=0 (default)
To fail when NNN or more errors are found:
- Snowflake: ON_ERROR=SKIP_FILE_NNN
- Redshift: MAXERROR=NNN
- Postgres (with your patch): REJECT_LIMIT=NNN-1 and ON_ERROR=ignore
- Postgres (with my idea): IGNORE_ERRORS=NNN
Thanks for the summary.
This makes me think it might be better to treat REJECT_LIMIT as
an additional option for ON_ERROR=stop instead of ON_ERROR=ignore
if we adopt your patch. Since ON_ERROR=stop is the default,
users could set the maximum number of allowed errors by specifying
only REJECT_LIMIT. Otherwise, they would need to specify both
ON_ERROR=ignore and REJECT_LIMIT.
That makes sense.
--
Regards,
--
Atsushi Torikoshi
NTT DATA Group Corporation
