Expand the system directory

After performing redistribution, the system will automatically generate the following system directories (including system tables, system views, etc.) and store them in the matrixmgr_internal mode of the matrixmgr database.

  • expand_status_summary
  • expand_status_detail
  • expand_expansion_progress

1.1 expand_status_summary

This table records the time information of the state of each stage of data redistribution, including the following fields:

Field Name Type Description
status text Track the status of a capacity expansion operation, the valid value is:
SCHEDULED START, which refers to the time when the redistribution is made to begin.
SETUP, which represents the start time when the database data table information is collected
SETUP DONE, which refers to the time when the data table information is collected
EXPANSION STARTED, which refers to the time when the data redistribution is officially started
COMPLETED, which refers to the time when all redistribution tasks are completed
LAST SCHEDULED START, which refers to the time when all redistribution tasks are completed, save the value of SCHEDULED START to LAST SCHEDULED START, and then clear SCHEDULED START
updated_at timestamp with time zone Timestamp for the last state change

1.2 expand_status_detail

This table contains status information of the tables involved in expansion. You can query this table to determine the status of the table being redistributed, or view the start and end times of the completed table. If there is no record in this table, it means no redistribution is required. This table also stores information about the table, such as OID.

Field Name Type Description
dbname text Name of the database to which the table belongs
db_oid oid Oid of the database to which the table belongs
fq_name text fully qualified name of the table
table_oid oid table OID
root_partition_name text For partition tables, it is the name of the root partition. Otherwise it is None
rank int Level determines the order in which the table is expanded. The expansion tool will be sorted on the rank, and tables with smaller numbers will be processed earlier
external_writable boolean Identify whether the table is an external writable table. (External writable tables require different syntax to expand capacity)
status text The current expansion status of this table. Valid values are:
NOT STARTED
IN PROGRESS
PENDING
RETRYING
COMPLETED
FAILED
expansion_started_at timestamp with time zone timestamp at which the expansion of this table begins
expansion_finished_at timestamp with time zone timestamp for the expansion of this table. This time stamp will also be updated if the expansion fails
source_bytes numeric The amount of data that has not been redistributed. Due to the table expansion in the HEAP table and the number of segments after expansion, the expanded size will also be different from the source table. This table provides progress information and estimates the duration of the expansion process
failed_times integer Retry times, default value is 5

1.3 expand_expansion_progress

This system directory is a view containing information on the overall status of the expansion, providing an estimate of the table redistribution speed and time to complete all data redistribution.

Field Name Type Description
name text The metric name that describes the expansion process, including:
Bytes Pending
Bytes in Progress
Bytes Done
Bytes Failed
Estimated Expansion Rate
Estimated Remaining Time
Done Tables Number
Pending Tables Number
In Progress Tables Number
Failed Tables Number
value text The value of the above indicator. For example, Bytes Pending: 100023434