# KeyDB
**Domain:** Data Infrastructure / Embedded Storage / Project History
**Doc Type:** Project Technology Node
**Maturity:** Developed
**Related:** [[wiki/Symbolic Language Engine|Symbolic Language Engine]], [[wiki/Corpus Engineering|Corpus Engineering]], [[wiki/Shazam Perl Library|Shazam Perl Library]], [[wiki/Multi-Index Language Representation|Multi-Index Language Representation]], [[wiki/Provenance|Provenance]]
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## Definition
**KeyDB is Bryant McGill's lightweight key-value storage format and Perl access module, built for portable corpus pipelines and applications that did not require a separately administered database server.**
The text format stores one key-value record per line with a pipe delimiter and an escaping layer for literal pipes and newlines. The module developed a broader operational surface including locking, merge-and-write, overwrite, deletion, counters, unique key assignment, bulk replacement and a binary path using Perl's `Storable` where parse speed mattered.
## Symbolic Language Engine Context
KeyDB supported the manufacture and storage of derived linguistic representations and indexes. It was designed for software capable of running from a portable folder or thumb drive, where external database administration would have undermined the product architecture.
An internal annotation—`Modified: Bryant — 4.27.2001`—provides unusually strong artifact-level dating because it exists inside the surviving module rather than being inferred from later promotional material.
## Continuity
The same pipe-delimited convention continued serving Bryant McGill's website twenty-five years later. That survival demonstrates the difference between fashionable infrastructure and a stable representation whose constraints remain understood.
## Key Insight
**KeyDB made persistence cheap enough that linguistic experimentation could remain portable, inspectable and under the author's direct control.**
## See Also
[[wiki/Shazam Perl Library|Shazam Perl Library]], [[wiki/Corpus Engineering|Corpus Engineering]], [[wiki/Multi-Index Language Representation|Multi-Index Language Representation]], [[wiki/Symbolic Language Engine|Symbolic Language Engine]], [[wiki/Provenance|Provenance]], [[wiki/Technical Archaeology|Technical Archaeology]]
## Sources / Provenance
- Surviving KeyDB Perl module and internal 2001 annotation.
- Project architecture described in [[projects/Ten Years Building a Symbolic Language Engine|Ten Years Building a Symbolic Language Engine]].