23.5.14.37 The ndbinfo memory_per

23.5.14.37 The ndbinfo memory_per_fragment Table

The memory_per_fragment table provides information about the usage of memory by individual fragments.

The memory_per_fragment table contains the following columns:

fq_name
Name of this fragment
parent_fq_name
Name of this fragment's parent
type
Type of object; see text for possible values
table_id
Table ID for this table
node_id
Node ID for this node
block_instance
Kernel block instance ID
fragment_num
Fragment ID (number)
fixed_elem_alloc_bytes
Number of bytes allocated for fixed-sized elements
fixed_elem_free_bytes
Free bytes remaining in pages allocated to fixed-size elements
fixed_elem_size_bytes
Length of each fixed-size element in bytes
fixed_elem_count
Number of fixed-size elements
fixed_elem_free_count
Number of free rows for fixed-size elements
var_elem_alloc_bytes
Number of bytes allocated for variable-size elements
var_elem_free_bytes
Free bytes remaining in pages allocated to variable-size elements
var_elem_count
Number of variable-size elements
hash_index_alloc_bytes
Number of bytes allocated to hash indexes

Notes

The type column from this table shows the dictionary object type used for this fragment (Object::Type, in the NDB API), and can take any one of the values shown in the following list:

System table
User table
Unique hash index
Hash index
Unique ordered index
Ordered index
Hash index trigger
Subscription trigger
Read only constraint
Index trigger
Reorganize trigger
Tablespace
Log file group
Data file
Undo file
Hash map
Foreign key definition
Foreign key parent trigger
Foreign key child trigger
Schema transaction

You can also obtain this list by executing SELECT * FROM ndbinfo.dict_obj_types in the mysql client.

The block_instance column provides the NDB kernel block instance number. You can use this to obtain information about specific threads from the threadblocks table.