From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
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To: | Bruce Momjian <bruce(at)momjian(dot)us> |
Cc: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: COPY and file_fdw with fixed column widths |
Date: | 2015-04-28 19:46:22 |
Message-ID: | 34330.1430250382@sss.pgh.pa.us |
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Lists: | pgsql-hackers |
Bruce Momjian <bruce(at)momjian(dot)us> writes:
> I know COPY doesn't support importing files with fixed column widths,
> i.e. we can't say field1 is the first 30 characters, and field2 is the
> rest of the line. We need a unique delimiter at column 31. (Commercial
> Ingres does support this ability.)
> I know we tell most people to use sed, Perl, or an ETL tool to convert
> files into a format COPY understands, and I think that is a reasonable
> answer. However, the file_fdw also reads our COPY format, and in that
> case, the data file might be updated regularly and running an ETL
> process on it every time it is read is inconvenient.
COPY is, and has always been intended to be, as fast as possible; loading
format transformation abilities onto it seems like a fundamental mistake.
Therefore, if you wish file_fdw were more flexible, I think the answer is
to create a variant of file_fdw that doesn't use COPY but some other
mechanism.
regards, tom lane
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