PostgreSQL index naming convention to remember

PostgreSQL_index_naming.rst

The standard names for indexes in PostgreSQL are:

{tablename}_{columnname(s)}_{suffix}

where the suffix is one of the following:

• pkey for a Primary Key constraint;
• key for a Unique constraint;
• excl for an Exclusion constraint;
• idx for any other kind of index;
• fkey for a Foreign key;
• check for a Check constraint;

Standard suffix for sequences is

seq for all sequences

Found here

And also, why not to make them prefix (not suffix) for better readability?

It was found here:
https://stackoverflow.com/questions/4107915/postgresql-default-constraint-names/4108266#4108266
Copied it to gist just in case (if I forget where to look for it)

That's not so.

I created an index for the core_paymentdocument_2023_01_21 table and PG named it core_paymentdocument_2023_01__cashbox_number_currency_stat_idx.

I created an index for the core_paymentdocument_2023_01_22 table and PG named it core_paymentdocument_2023_01__cashbox_number_currency_stat_idx1.

Why did PG crop the table name?

@kozlovalex index name length limit is 64 bytes.