Understanding Table and Index Values

Querying the SYS.MEMORYANALYTICS table provides run-time information about the tables and indexes available in SQLFire.

Table Values

Each table has a single row in SYS.MEMORYANALYTICS identitfied with the SQLENTITY format: schema_name.table_name (Entry Size, Value Size, Row Count). The ID column value displays the values separated by commas.
Table Value Description
Entry Size The per-entry overhead, in bytes. (This excludes the Value Size below.)
Value Size The total size of a table row, in bytes. (This includes the Entry Size overhead.)
Row Count The total number of rows stored on the local SQLFire member. For a partitioned table, this includes all buckets for the table, as well as primary and secondary replicas.
For example, the following row from SYS.MEMORYANALYTICS shows that the APP.FLIGHTS table has 30352 bytes of overhead per row, with 542 total rows:
SQLENTITY                
               |ID                 
                              |MEMORY
----------------------------------------------------------------
APP.FLIGHTS (Entry Size, Value Size, Row Count)   
               |dyozie-e4310(6880)<v0>:3439/59731
                              |30352,31436,542

Index Values

Each index has two rows in SYS.MEMORYANALYTICS. The first row uses the SQLENTITY format: schema_name.table_name.index_name (Index Entry Overhead, SkipList Size, Max Level). This row provides details about concurrent skip lists for the index. The ID column value displays these values separated by commas:
Index Value Description
Index Entry Overhead The number of linked list objects that the index uses for storing the entry.
SkipList Size The number of linked list objects that the index uses for skipping values to expedite searches.
Max Level The total number of skip lists that are currently available for lookups.
For example, the following row from SYS.MEMORYANALYTICS shows that APP.FLIGHTS.DESTINDEX uses 2803 bytes for skip lists:
SQLENTITY                
               |ID                 
                              |MEMORY
----------------------------------------------------------------
APP.FLIGHTS.DESTINDEX (Index Entry Overhead, SkipList Size, Max&
               |dyozie-e4310(6880)<v0>:3439/59731
                              |2104,696,3 (2803 = 2.74 kb)
The second row for an index uses the SQLENTITY format: schema_name.table_name.index_name (Index Entry Size, Value Size, Row Count). This row provides information similar to the values for a table entry. The ID column value displays these values separated by commas:
Index Value Description
Index Entry Size The per-index overhead, in bytes. (This includes the Index Entry Overhead from the previous table, but excludes the Value Size below.)
Value Size The size of the data structure used to point to the underlying region entries, in bytes. For a unique index, this corresponds to the size of a pointer reference.
Row Count The total number of entries in the index.
For example, the following row from SYS.MEMORYANALYTICS shows that APP.FLIGHTS.DESTINDEX has 4888 bytes of overhead with 87 index entries:
SQLENTITY                
               |ID                 
                              |MEMORY
----------------------------------------------------------------
APP.FLIGHTS.DESTINDEX (Index Entry Size, Value Size, Row Count) 
               |dyozie-e4310(6880)<v0>:3439/59731
                              |4888,3784,87