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diff --git a/contrib/pg_dumplo/README.pg_dumplo b/contrib/pg_dumplo/README.pg_dumplo deleted file mode 100644 index a7d6625d203..00000000000 --- a/contrib/pg_dumplo/README.pg_dumplo +++ /dev/null @@ -1,148 +0,0 @@ -$PostgreSQL: pgsql/contrib/pg_dumplo/README.pg_dumplo,v 1.3 2003/11/29 19:51:35 pgsql Exp $ - -pg_dumplo - PostgreSQL large object dumper -========================================== - -By Karel Zak <zakkr@zf.jcu.cz> - - -Compilation: -=========== - - * run master ./configure in the PG source top directory - * gmake all - * gmake install - -THANKS: -====== - - <??? I lost his e-mail ???> - * option '--all' and pg_class usage - - Pavel Janík ml. <Pavel.Janik@linux.cz> - * HOWTO (the rest of this file) - - -How to use pg_dumplo? -===================== - -(c) 2000, Pavel Janík ml. <Pavel.Janik@linux.cz> - - -Q: How do you use pg_dumplo? -============================ - -A: This is a small demo of backing up the database table with Large Objects: - - -We will create a demo database and a small and useless table `lo' inside -it: - -SnowWhite:$ createdb test -CREATE DATABASE - -Ok, our database with the name 'test' is created. Now we should create demo -table which will contain only one column with the name 'id' which will hold -the OID number of a Large Object: - -SnowWhite:$ psql test -Welcome to psql, the PostgreSQL interactive terminal. - -Type: \copyright for distribution terms - \h for help with SQL commands - \? for help on internal slash commands - \g or terminate with semicolon to execute query - \q to quit - -test=# CREATE TABLE lo (id oid); -CREATE -test=# \lo_import /etc/aliases -lo_import 19338 -test=# INSERT INTO lo VALUES (19338); -INSERT 19352 1 -test=# select * from lo; - id -------- - 19338 -(1 row) - -test=# \q - -In the above example you can see that we have also imported one "Large -Object" - the file /etc/aliases. It has an oid of 19338 so we have inserted -this oid number to the database table lo to the column id. The final SELECT -shows that we have one record in the table. - -Now we can demonstrate the work of pg_dumplo. We will create a dump directory -which will contain the whole dump of large objects (/tmp/dump): - -mkdir -p /tmp/dump - -Now we can dump all large objects from the database `test' which have OIDs -stored in the column `id' in the table `lo': - -SnowWhite:$ pg_dumplo -s /tmp/dump -d test -l lo.id -pg_dumplo: dump lo.id (1 large obj) - -Voila, we have the dump of all Large Objects in our directory: - -SnowWhite:$ tree /tmp/dump/ -/tmp/dump/ -`-- test - |-- lo - | `-- id - | `-- 19338 - `-- lo_dump.index - -3 directories, 2 files -SnowWhite:$ - -In practice, we'd probably use - -SnowWhite:$ pg_dumplo -s /tmp/dump -d test -e - -to export all large objects that are referenced by any OID-type column -in the database. Calling out specific column(s) with -l is only needed -for a selective dump. - -For routine backup purposes, the dump directory could now be converted into -an archive file with tar and stored on tape. Notice that a single dump -directory can hold the dump of multiple databases. - -Now, how can we recreate the contents of the table lo and the Large Object -database when something went wrong? To do this, we expect that pg_dump is -also used to store the definition and contents of the regular tables in -the database. - -SnowWhite:$ pg_dump test >test.backup - -Now, if we lose the database: - -SnowWhite:$ dropdb test -DROP DATABASE - -we can recreate it and reload the regular tables from the dump file: - -SnowWhite:$ createdb test -CREATE DATABASE - -SnowWhite:$ psql test <test.backup - -But at this point our database has no large objects in it. What's more, -the large-object-referencing columns contain the OIDs of the old large -objects, which will not be the OIDs they'll have when reloaded. Never -fear: pg_dumplo will fix the large object references at the same time -it reloads the large objects. We reload the LO data from the dump -directory like this: - -SnowWhite:$ pg_dumplo -s /tmp/dump -d test -i -19338 lo id test/lo/id/19338 -SnowWhite:$ - -And this is everything. The contents of table lo will be automatically -updated to refer to the new large object OIDs. - -Summary: In this small example we have shown that pg_dumplo can be used to -completely dump the database's Large Objects very easily. - -For more information see the help ( pg_dumplo -h ). |