Common errors

Maximum number of partitions exceeded

Scenario: The following error message appears when you query data in a partitioned table:

ERROR: AXF Exception: specified partitions count in odps table: <project_name.table_name> is: xxx, exceeds the limitation of xxx, please add stricter partition filter

Cause: To guarantee the query performance, Hologres can scan a maximum of 50 partitions from a partitioned table during a single query.

Workaround: We recommend that you change the data table to be queried to a non-partitioned table or a partitioned table with fewer than 50 partitions before querying data in the table.

Transaction error

Scenario: The following error message appears when you execute an SQL statement:

ERROR: current transaction is aborted, commands ignored until end of transaction block

Cause: A new SQL statement is executed when the previous SQL statement is still in progress.

Workaround: Run the rollback command.

I/O error

Scenario: The following error message appears when you execute an SQL statement:

An I/O error occurred while sending to the backbend

Workaround: Refresh the page and re-execute the SQL statement.

DataService Studio or JDBC connection error

Scenario: The following error message appears when you connect to Hologres through DataWorks DataService Studio or Java Database Connectivity (JDBC):

SQL state [XX000]; error code [0]; ERROR: Query could not generate plan by gporca : GPDB Expression type: Query Parameter not supported in DXL; nested exception is org.postgresql.util.PSQL

Cause: Required extension parameters are absent in the connection string.

Workaround: Append the required extension parameters to the end of the connection string. The correct connection string is as follows:

jdbc:postgresql://endpoint:port/dbname? preferQueryMode=simple&tcpKeepAlive=true

Error thrown during data query in a foreign table

Scenario: The following error message appears when you query MaxCompute data in a foreign table:

ERROR: Query:[100181047458824706] Get result failed: exec sql failed => status:7 msg:ERROR: External table size 268911MB exceeded the maximum cache size 204800MB

Cause: Hologres can scan a maximum of 200 GB data from a foreign table during a single query, but the foreign table contains more than 200 GB data.