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Created March 30, 2018 00:01
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why_database_name_only_63_characters_long.md

Why length of table name is limited to 63 characters long?

The default limit on length of identifiers in PostGreSQL is 63 because value of NAMEDATALEN constant is 64 by default. The length of identifiers is NAMEDATALEN - 1 which becomes 64 - 1 equal to 63.

This configuration can't be changed without compiling PostGreSQL again. We use name of the repository and name of branch to dynamically calculate database name for every branch. But if the length of this combination becomes greater than 63 then it gives error:

Input string is longer than NAMEDATALEN-1 (63)

To avoid this, we have restricted the length of the database name to maximum 63 characters. This has a possible side-effect that 2 branches with long names and similar characters upto length 63 will have same database name. But it is very unlikely.

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