This topic describes how to use the Simple storage policy in the spatio-temporal database Ganos.

Background information

Spatio-temporal data features large data objects and the total amount of spatio-temporal data is large. In most cases, data of the types, such as grids, trajectories, and point clouds, in Ganos must be compressed by using professional compression algorithms and then stored in database tables. The storage policy provided by the current database supports only fixed and simple compression algorithms. Data can also be stored in external tables without being compressed. Due to this policy, spatio-temporal occupies a lot of storage space and affects query performance.

Therefore, a simple storage policy called Simple is provided in Ganos. This policy allows you to use a custom compression algorithm to compress data before the data is stored. The compressed data is stored in basic tables if possible. The policy reduces storage costs, and the impact on query performance as much as possible.

Use the policy

Specify the Grand Unified Configuration (GUC) parameter. By default, this parameter is enabled.

  • To enable the GUC parameter, execute the following statement:
    SET polar_enable_storage_simple=true;
  • To disable the GUC parameter, execute the following statement:
    SET polar_enable_storage_simple=false;

Set the specified field of the table to storage simple, as shown in the following example:

ALTER TABLE tbname ALTER colname SET storage simple;

After the settings are complete, the colname field is automatically stored based on the Simple storage policy.