array_metadata.md

Array Metadata

Main Structure

The array metadata is a folder called __meta located here:

my_array                            # array folder
   |  ...
   |_ __meta                        # array metadata folder
         |_ <timestamped_name>      # array metadata file
         |_ ...  
         |_ <timestamped_name>.vac  # vacuum file
         |_ ...  

<timestamped_name> has format __t1_t2_uuid_v, where:

• t1 and t2 are timestamps in milliseconds elapsed since 1970-01-01 00:00:00 +0000 (UTC)
• uuid is a unique identifier
• v is the format version

The array metadata folder can contain:

• Any number of array metadata files
• Any number of vacuum files

Array Metadata File

The array metadata file has the following on-disk format:

Field	Type	Description
Key length	uint32_t	The length of the key.
Key	uint8_t[]	The key.
Deletion	char	1/0 if it is a deletion/insertion.
Value type	char	The value data type. Present only if del is 0.
Number of values	uint32_t	The number of values. Present only if del is 0.
Value	uint8_t[]	The value. Present only if del is 0.