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Asked: 2026-05-15T06:28:07+00:00

Whenever I design a database I automatically start with an auto-generating GUID primary key

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Whenever I design a database I automatically start with an auto-generating GUID primary key for each of my tables (excepting look-up tables)

I know I’ll never lose sleep over duplicate keys, merging tables, etc. To me it just makes sense philosophically that any given record should be unique across all domains, and that that uniqueness should be represented in a consistent way from table to table.

I realize it will never be the most performant option, but putting performance aside, I’d like to know if there are philosophical arguments against this practice?

Based on the responses let me clarify:

I’m talking about consistently using a GUID surrogate key as a primary key- irrespective of whether and how any natural or sequential keys are designed on a table. These are my assumptions:

  1. Data integrity based on natural keys can be designed for, but not assumed.
  2. A primary key’s function is referential integrity, irrespective of performance, sequencing, or data.
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  1. Editorial Team

    Jeff Atwood talks about this in great detail:
    http://www.codinghorror.com/blog/2007/03/primary-keys-ids-versus-guids.html

    Guid Pros:
    Unique across every table, every database, every server
    Allows easy merging of records from different databases
    Allows easy distribution of databases across multiple servers
    You can generate IDs anywhere, instead of having to roundtrip to the database
    Most replication scenarios require GUID columns anyway

    Guid Cons:
    It is a whopping 4 times larger than the traditional 4-byte index value; this can have serious performance and storage implications if you’re not careful
    Cumbersome to debug (where userid='{BAE7DF4-DDF-3RG-5TY3E3RF456AS10}’)
    The generated GUIDs should be partially sequential for best performance (eg, newsequentialid() on SQL 2005) and to enable use of clustered indexes

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