From: schabi at logix-tt.com (Markus Schaber) Date: Fri, 29 Sep 2006 15:37:28 +0200 Subject: [Pljava-dev] VarLenTuple example code In-Reply-To: <451D10E0.8020003@tada.se> References: <451BD0B1.8000408@logix-tt.com> <451BD2F4.60202@tada.se> <451BD650.2080201@logix-tt.com> <451BDB5E.1020107@tada.se> <451BE12B.6060809@logix-tt.com> <451BF32A.7000405@tada.se> <451CF211.7000000@logix-tt.com> <451CFAAD.9030603@tada.se> <451D0B0B.4010008@logix-tt.com> <451D10E0.8020003@tada.se> Message-ID: <451D2198.7050202@logix-tt.com> Hi, Thomas, Thomas Hallgren wrote: >> But C is the one that's stored on disk by PostgreSQL, neither D nor B. > Now I'm confused. I though you said C was the internal representation? Yes, as I described it in Message-ID: <45183343.8000105 at logix-tt.com> rsp. http://gborg.postgresql.org/pipermail/pljava-dev/2006/000925.html - at least that's how I thought things work in PostgreSQL: > C) is what PostgreSQL passes around (to PostGIS C functions as well as > to the PLJava glue code), and stores on disk. The size is defined as ^^^^^^^^^^^^^^^^^^ > "internallength" in the datatype, and contained in a 4-byte VARLEN > header for variable length datatypes which have internallength set to > -1. (let's ignore TOAST and 0-terminated Strings for simplification.) It's "internal" in the sense that it is not visible to clients outside of the Postmaster. Clients (including pg_dump/pg_restore and the COPY formats) see what output/input (A) and send/receive (B) produce and consume, depending on whether they use text and binary mode. But as far as I can tell, PostgreSQL does not use send/receive before writing the tuple data on disk. At least that is what I believed so far, I'm rather irritated now and I'm going to double- and triple-check that immediately. Thanks, Markus -- Markus Schaber | Logical Tracking&Tracing International AG Dipl. Inf. | Software Development GIS Fight against software patents in Europe! www.ffii.org www.nosoftwarepatents.org -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 252 bytes Desc: OpenPGP digital signature URL: