Lossless transmission of double precision floating point - Mailing list pgsql-hackers

From Michael J. Baars
Subject Lossless transmission of double precision floating point
Date
Msg-id CALudE+7BkAWP721SLnC6vSqo3hwQtqpK3s41bPqtr266y97bFg@mail.gmail.com
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Responses Re: Lossless transmission of double precision floating point
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Hi,

I receive data from a data provider on a daily basis, and noticed how they use fixed type floating point in text mode, to transmit data. As you might know, this type of transmission is not lossless.

Because the PostgreSQL binary format is not very portable across different database providers, I came up with two solutions to this problem.

1) Pass an optional custom binary format loader to the COPY command.
2) Lossless transmission in text mode through byte arrays.

1) You already seem to be working on that, but are other database providers too?
2) I attached some code, but the COPY command refuses to accept custom implicit typecasts. Correct? Adding dedicated casting columns seems to be the accepted work around.

This is not a problem that needs to be solved immediately, but in the long run, a COPY command that does accept custom implicit typecasts would be very much appreciated.

Kind regards,
Mischa.
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