How to check consistency at the end of a transaction


DEFERRED CONSTRAINTS are useful when you know that in a transaction you'll have inconsistent data for a while, like foreign keys that don't match, but you know that at the end of a transaction it will be consistent.

It was a nice PostgreSQL surprise to discover DEFERRED CONSTRAINTS, because it's not present in many . . .

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Posted in: postgresql

December 19, 2017

PostgreSQL "Could not resolve client IP address to a host name" error

Using hostnames in pg_hba.conf

Since PostgreSQL 9.1 it's possible to use host names in pg_hba.conf.

I'm using it in a server and I got this error from a Java's client application trying to connect to it:

Caused by: org.postgresql.util.PSQLException: FATAL: no pg_hba.conf entry for host "", user "my_user", database . . .

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Posted in: postgresql

June 03, 2016

SQL Server vs PostgreSQL: fighting for resources in the same server


Notice: This is not the typical performance’s comparative between SQL Server and PostgreSQL. I only test their performance’s affectation when they run in the same server, that I would never do.

We were asked: “Is it possible to run SQL Server and a PostgreSQL in the same server?”

Obviously, the server would run under Windows. . . .

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April 20, 2016