Pivotal Greenplum 6.9 Release Notes

Pivotal Greenplum 6.9 Release Notes

This document contains pertinent release information about Pivotal Greenplum Database 6.9 releases. For previous versions of the release notes for Greenplum Database, go to Pivotal Greenplum Database Documentation. For information about Greenplum Database end of life, see Pivotal Greenplum Database end of life policy.

Pivotal Greenplum 6 software is available for download from the Pivotal Greenplum page on Pivotal Network.

Pivotal Greenplum 6 is based on the open source Greenplum Database project code.

Important: Pivotal Support does not provide support for open source versions of Greenplum Database. Only Pivotal Greenplum Database is supported by Pivotal Support.

Release 6.9.1

Release Date: 2020-07-24

Pivotal Greenplum 6.9.1 is a maintenance release that resolves several issues.

Note: Greenplum 6.9.1 also includes the Greenplum Database R Client (GreenplumR) version 1.1.0. This version of GreenplumR adds the input.signature argument to db.gpapply() and db.gptapply(), to match function argument names to table column names when the function input argument is not a single data frame. See Greenplum Database R Client.

Resolved Issues

Pivotal Greenplum 6.9.1 resolves these issues:

n/a
The DataDirect ODBC Drivers were updated to version 7.16.359 to incorporate hot fix changes and certify compatibility with SUSE Linux Enterprise Server 15 clients. See the DataDirect Release Notes for additional information.
30750
The ANALYZE code did not exclude external tables (which cannot be analyzed) if an external table was part of a table partition hierarchy. This would result in the failure ERROR: unsupported table type when performing partitioned table operations that use ANALYZE, such as ALTER TABLE … EXCHANGE PARTITION. The problem was resolved by updating the ANALYZE code to correctly exclude these external tables.

Release 6.9.0

Release Date: 2020-06-26

Pivotal Greenplum 6.9.0 is a minor release that includes changed features and resolves several issues.

Features

Greenplum Database 6.9.0 includes these new and changed features:

  • Greenplum Streaming Server (GPSS) version 1.4.0 is included, which introduces many new and changed features and bug fixes. Refer to the GPSS Release Notes for more information on release content and to access the GPSS documentation.
    Note: If you have previously used GPSS in your Greenplum 6.x installation, you are required to perform upgrade actions as described in Upgrading the Streaming Server.
  • PXF version 5.13.0 is included, the first PXF release to also provide a separate download package that enables you to install PXF in a file system location outside of the Greenplum install directory. Refer to the PXF Release Notes for more information on release content and supported platforms, and to access the PXF documentation.

Resolved Issues

Pivotal Greenplum 6.9.0 resolves these issues:

30630 - Segment Mirroring
In some cases during a failover of a segment instance, Greenplum Database returned the FATAL error requested WAL segment WAL_seg_ID has already been removed. Greenplum Database WAL replication incorrectly removed segment files before they were processed during failover. This issue is resolved.
10216 - ALTER TABLE, ALTER DOMAIN
In some cases, heap table data is lost when performing concurrent ALTER TABLE or ALTER DOMAIN commands where one command alters a table column and the other rewrites or redistributes the table data. For example, performing concurrent ALTER TABLE commands where one command changes a column data type from int to text might cause data loss. This issue might also occur when altering a table column during the data distribution phase of a Greenplum system expansion. Greenplum Database did not correctly capture the current state of the table during command execution. This issue is resolved.
10224 - ALTER TABLE
For a leaf partition of a partitioned table, ALTER TABLE allowed the distribution policy to be changed to REPLICATED. This is resolved. ALTER TABLE no longer allows the change.
30647 - Postgres Planner
Some queries that performed multistage aggregation returned results in the incorrect order. For example, some queries that perform a COUNT in the select list and also contain a GROUP BY clause returned results in the incorrect order. This issue is resolved.
10013 - Postgres Planner
In some cases, Greenplum Database generated a PANIC when it encountered a lateral subquery that included a LIMIT 1 or GROUP BY clause. Greenplum 6.9 resolves this issue by forcing the gathering and materialization of any relation containing a GROUP BY or LIMIT clause.
10315 Postgres Planner
For some queries that perform a FULL JOIN using a subselect that contains a COALESCE function, Greenplum Database returned "ERROR: could not find hash distribution key expressions in target list". This issue is resolved.
8919 - MPP, Query Execution
Greenplum Database did not properly handle concurrent updating operations to a table when one of the operations moved a table distribution key to another segment instance. Now when a table distribution key is moved to another segment instance, a concurrent updating operation returns an error.
173243811 - Resource Groups
When resource groups are enabled and a user attempted to move a running query from one resource group to a resource group configured using the memory_limit=0 with the pg_resgroup_move_query() function, Greenplum Database returned the error ERROR: group <group_ID> doesn't have enough memory on master. This issue is resolved.
172931886 - Transaction System
Greenplum 6.9 resolves an issue where restarting a primary could lead to a segment process hang when there were prepared, but not yet committed or aborted, transactions in progress at the time of shutdown.

Upgrading from Greenplum 6.x to Greenplum 6.9

Note: Greenplum 6 does not support direct upgrades from Greenplum 4 or Greenplum 5 releases, or from earlier Greenplum 6 Beta releases.

See Upgrading from an Earlier Greenplum 6 Release to upgrade your existing Greenplum 6.x software to Greenplum 6.9.0.

Deprecated Features

Deprecated features will be removed in a future major release of Greenplum Database. Pivotal Greenplum 6.x deprecates:

  • The gpsys1 utility.
  • The analzyedb option --skip_root_stats (deprecated since 6.2).

    If the option is specified, a warning is issued stating that the option will be ignored.

  • The server configuration parameter gp_statistics_use_fkeys (deprecated since 6.2).
  • The server configuration parameter gp_ignore_error_table (deprecated since 6.0).

    To avoid a Greenplum Database syntax error, set the value of this parameter to true when you run applications that execute CREATE EXTERNAL TABLE or COPY commands that include the now removed Greenplum Database 4.3.x INTO ERROR TABLE clause.

  • Specifying => as an operator name in the CREATE OPERATOR command (deprecated since 6.0).
  • The Greenplum external table C API (deprecated since 6.0).

    Any developers using this API are encouraged to use the new Foreign Data Wrapper API in its place.

  • Commas placed between a SUBPARTITION TEMPLATE clause and its corresponding SUBPARTITION BY clause, and between consecutive SUBPARTITION BY clauses in a CREATE TABLE command (deprecated since 6.0).

    Using this undocumented syntax will generate a deprecation warning message.

  • The timestamp format YYYYMMDDHH24MISS (deprecated since 6.0).

    This format could not be parsed unambiguously in previous Greenplum Database releases, and is not supported in PostgreSQL 9.4.

  • The createlang and droplang utilities (deprecated since 6.0).
  • The pg_resqueue_status system view (deprecated since 6.0).

    Use the gp_toolkit.gp_resqueue_status view instead.

  • The GLOBAL and LOCAL modifiers when creating a temporary table with the CREATE TABLE and CREATE TABLE AS commands (deprecated since 6.0).

    These keywords are present for SQL standard compatibility, but have no effect in Greenplum Database.

  • Using WITH OIDS or oids=TRUE to assign an OID system column when creating or altering a table (deprecated since 6.0).
  • Allowing superusers to specify the SQL_ASCII encoding regardless of the locale settings (deprecated since 6.0).

    This choice may result in misbehavior of character-string functions when data that is not encoding-compatible with the locale is stored in the database.

  • The @@@ text search operator (deprecated since 6.0).

    This operator is currently a synonym for the @@ operator.

  • The unparenthesized syntax for option lists in the VACUUM command (deprecated since 6.0).

    This syntax requires that the options to the command be specified in a specific order.

  • The plain pgbouncer authentication type (auth_type = plain) (deprecated since 4.x).

Migrating Data to Greenplum 6

Note: Greenplum 6 does not support direct upgrades from Greenplum 4 or Greenplum 5 releases, or from earlier Greenplum 6 Beta releases.

See Migrating Data from Greenplum 4.3 or 5 for guidelines and considerations for migrating existing Greenplum data to Greenplum 6, using standard backup and restore procedures.

Known Issues and Limitations

Pivotal Greenplum 6 has these limitations:

  • Upgrading a Greenplum Database 4 or 5 release, or Greenplum 6 Beta release, to Pivotal Greenplum 6 is not supported.
  • MADlib, GPText, and PostGIS are not yet provided for installation on Ubuntu systems.
  • Greenplum 6 is not supported for installation on DCA systems.
  • Greenplum for Kubernetes is not yet provided with this release.

The following table lists key known issues in Pivotal Greenplum 6.x.

Table 1. Key Known Issues in Pivotal Greenplum 6.x
Issue Category Description
N/A Spark Connector This version of Greenplum is not compatible with Greenplum-Spark Connector versions earlier than version 1.7.0, due to a change in how Greenplum handles distributed transaction IDs.
N/A PXF Starting in 6.x, Greenplum does not bundle cURL and instead loads the system-provided library. PXF requires cURL version 7.29.0 or newer. The officially-supported cURL for the CentOS 6.x and Red Hat Enterprise Linux 6.x operating systems is version 7.19.*. Greenplum Database 6 does not support running PXF on CentOS 6.x or RHEL 6.x due to this limitation.

Workaround: Upgrade the operating system of your Greenplum Database 6 hosts to CentOS 7+ or RHEL 7+, which provides a cURL version suitable to run PXF.

29703 Loading Data from External Tables Due to limitations in the Greenplum Database external table framework, Greenplum Database cannot log the following types of errors that it encounters while loading data:
  • data type parsing errors
  • unexpected value type errors
  • data type conversion errors
  • errors returned by native and user-defined functions
LOG ERRORS returns error information for data exceptions only. When it encounters a parsing error, Greenplum terminates the load job, but it cannot log and propagate the error back to the user via gp_read_error_log().

Workaround: Clean the input data before loading it into Greenplum Database.

30594 Resource Management Resource queue-related statistics may be inaccurate in certain cases. Pivotal recommends that you use the resource group resource management scheme that is available in Greenplum 6.
30522 Logging Greenplum Database may write a FATAL message to the standby master or mirror log stating that the database system is in recovery mode when the instance is synchronizing with the master and Greenplum attempts to contact it before the operation completes. Ignore these messages and use gpstate -f output to determine if the standby successfully synchronized with the Greenplum master; the command returns Sync state: sync if it is synchronized.
30537 Postgres Planner The Postgres Planner generates a very large query plan that causes out of memory issues for the following type of CTE (common table expression) query: the WITH clause of the CTE contains a partitioned table with a large number partitions, and the WITH reference is used in a subquery that joins another partitioned table.

Workaround: If possible, use the GPORCA query optimizer. With the server configuration parameter optimizer=on, Greenplum Database attempts to use GPORCA for query planning and optimization when possible and falls back to the Postgres Planner when GPORCA cannot be used. Also, the specified type of query might require a long time to complete.

170824967 gpfidsts For Greenplum Database 6.x, a command that accesses an external table that uses the gpfdists protocol fails if the external table does not use an IP address when specifying a host system in the LOCATION clause of the external table definition.
n/a Materialized Views By default, certain gp_toolkit views do not display data for materialized views. If you want to include this information in gp_toolkit view output, you must redefine a gp_toolkit internal view as described in Including Data for Materialized Views.
168957894 PXF The PXF Hive Connector does not support using the Hive* profiles to access Hive transactional tables.

Workaround: Use the PXF JDBC Connector to access Hive.

168548176 gpbackup When using gpbackup to back up a Greenplum Database 5.7.1 or earlier 5.x release with resource groups enabled, gpbackup returns a column not found error for t6.value AS memoryauditor.
164791118 PL/R PL/R cannot be installed using the deprecated createlang utility, and displays the error:
createlang: language installation failed: ERROR:
no schema has been selected to create in
Workaround: Use CREATE EXTENSION to install PL/R, as described in the documentation.
N/A Greenplum Client/Load Tools on Windows The Greenplum Database client and load tools on Windows have not been tested with Active Directory Kerberos authentication.

Differences Compared to Open Source Greenplum Database

Pivotal Greenplum 6.x includes all of the functionality in the open source Greenplum Database project and adds:
  • Product packaging and installation script
  • Support for QuickLZ compression. QuickLZ compression is not provided in the open source version of Greenplum Database due to licensing restrictions.
  • Support for data connectors:
    • Greenplum-Spark Connector
    • Greenplum-Informatica Connector
    • Greenplum-Kafka Integration
    • Greenplum Streaming Server
  • Data Direct ODBC/JDBC Drivers
  • gpcopy utility for copying or migrating objects between Greenplum systems
  • Support for managing Greenplum Database using Pivotal Greenplum Command Center
  • Support for full text search and text analysis using Pivotal GPText
  • Greenplum backup plugin for DD Boost
  • Backup/restore storage plugin API (Beta)