HarperDB Limits

This document outlines limitations of HarperDB.

Schema Naming Restrictions

Case Sensitivity

HarperDB schema metadata (schema names, table names, and attribute/column names) are case sensitive. Meaning schemas, tables, and attributes can differ only by the case of their characters.

 

Restrictions on Schema Metadata Names

HarperDB schema metadata (schema names, table names, and attribute names) cannot contain the following UTF-8 characters:

/`¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ

Additionally, they cannot contain the first 31 non-printing characters. Spaces are allowed, but not recommended as best practice. The regular expression used to verify a name is valid is:

^[\x20-\x2E|\x30-\x5F|\x61-\x7E]*$

 

Table Limitations

Attribute Maximum

HarperDB 2.3.1 and up limits tables to 10,000 attributes. For 2.3.0 and below, the limit is 1,000 attributes.