Number of parts in an index
For TREE or HASH indexes, the maximum is 255 (
box.schema.INDEX_PART_MAX). For RTREE indexes, the maximum is 1 but the field is an ARRAY of up to 20 dimensions. For BITSET indexes, the maximum is 1.
Number of indexes in a space
Number of fields in a tuple
The theoretical maximum is 2,147,483,647 (
box.schema.FIELD_MAX). The practical maximum is whatever is specified by the space’s field_count member, or the maximal tuple length.
Number of bytes in a tuple
The maximal number of bytes in a tuple is roughly equal to memtx_max_tuple_size or vinyl_max_tuple_size (with a metadata overhead of about 20 bytes per tuple, which is added on top of useful bytes). By default, the value of either
vinyl_max_tuple_sizeis 1,048,576. To increase it, specify a larger value when starting the Tarantool instance. For example,
Number of bytes in an index key
If a field in a tuple can contain a million bytes, then the index key can contain a million bytes, so the maximum is determined by factors such as Number of bytes in a tuple, not by the index support.
Number of elements in array fields in a space with a multikey index
In a Tarantool space that has multikey indexes, any tuple cannot contain more than ~8,000 elements in a field indexed with that multikey index. This is because every element has 4 bytes of metadata, and the tuple’s metadata, which includes multikey metadata, cannot exceed 2^16 bytes.
Number of spaces
The theoretical maximum is 2147483647 (
box.schema.SPACE_MAX) but the practical maximum is around 65,000.
Number of connections
The practical limit is the number of file descriptors that one can set with the operating system.
The total maximum size for all spaces is in effect set by memtx_memory, which in turn is limited by the total available memory.
Update operations count
The maximum number of operations per tuple that can be in a single update is 4000 (
Number of users and roles
Length of an index name or space name or user name
Number of replicas in a replica set