Module string 

String and FixedString column types. String column implementations

ClickHouse Documentation:

• String
  • Variable-length UTF-8 strings
• FixedString
  • Fixed-length binary strings

String Type

Variable-length UTF-8 strings. Each string is prefixed with its length (varint encoded).

Wire Format:

For each string: [length:varint][bytes:UInt8 * length]

FixedString Type

Fixed-length binary strings, zero-padded if shorter than the specified size. Useful for storing UUIDs, hashes, or other fixed-size binary data.

Wire Format:

[bytes:UInt8 * N]  // N is the FixedString size

Structs

ColumnFixedString

Column for fixed-length strings (all strings padded to same length)

ColumnString

Column for variable-length strings