What types are binary incompatible in postgres?

Question

I was wondering if anyone knows which types are binary compatible or incompatible in Postgres.

I'm particularly interested in cases where a CREATE CAST from one type to another could cause Postgres to crash.

If someone happens to have a pointer to a matrix showing type (in)compatibility, that would be ideal.

Thanks in advance.

Craig Ringer · Accepted Answer · 2014-09-05 01:02:59Z

3

Data types that are binary-compatible generally already have WITHOUT FUNCTION casts defined for them.

A cast via a function is always safe, and not going to cause a problem.

If you want to add new WITHOUT FUNCTION casts, the only real reference is the source code, examining compatibility on a type-by-type basis.

answered Sep 5, 2014 at 1:02

Craig Ringer

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1 Comment

I noticed that the pg_cast table records possible casts from one data type to data type: postgresql.org/docs/8.3/static/catalog-pg-cast.html Some implicit conversion types appear here: docs.aws.amazon.com/redshift/latest/dg/r_Type_conversion.html