2. Postgres Pro Shardman Features #
Postgres Pro Shardman provides the most actual PostgreSQL
version with some additional patches applied and extensions added.
It includes new features developed by Postgres Professional,
third-party patches already accepted by the PostgreSQL community
for the upcoming PostgreSQL versions,
as well as a number of features inherited from
Postgres Pro Enterprise.
Postgres Pro Shardman users thus have early access
to important features and fixes.
Postgres Pro Shardman provides the following advantages,
compatibility features to your applications:
-
Strong ACID guarantees compared to other distributed databases.
-
Compatibility with
Postgres Pro Enterprise.
-
Several clusters support within a distributed cluster.
-
Transparent horizontal scaling
without a need in adopting NoSQL DBMS.
-
Built-in support of replication with no single point of failure,
with any node being able to become coordinator that requires
no system shut down and prevents any data loss.
-
Capacity of up to 100 cluster nodes.
-
High availability
with primary and stand-by modes, along with the synchronous solution for
the failover scenarios.
-
Tools
to support
REPEATABLE READ
isolation level in a distributed system, along with
advisory locks.
-
Work with cluster
as with a fully functional DBMS.
-
Backup and recovery
tools that support full and incremental backup with logs.
-
Point-in-time recovery (PITR)
as a consistent syncpoint.
-
Streaming replication.
-
High-availability cluster creation
with multiple primary nodes with special
utilities.
-
Stored procedures.
-
Full text search.
-
Covering indexes.
-
B-tree, hash, GiST, GIN, SP-GiST, BRIN
indexes.
-
Perl and
Python procedural languages.
-
ANSI SQL standard.
-
Storing and processing
of big amounts of data (1 PB and more).
-
Interfaces for C++, Ruby,
C,
ODBC,
Perl, Python, Tcl,
and Java.
-
EUC, UTF-8, and Mule
character set.
-
Compressed file system.
-
Access data stored in external PostgreSQL servers with
postgres_fdw.
-
In-built monitoring agent.
-
No limits for the number of
records or indexes, with the maximum table size of 32 TB,
maximum attribute size of 1 GB, and maximum number of attributes
of 1600.
-
Detailed access management
with different access levels and roles.
The following enhancements are also inherited from
Postgres Pro Enterprise:
- 64-bit transaction IDs that are not subject to wraparound.
(See Section 23.1.5.)
- Page-level compression. (See Chapter 31.)
-
Fair lightweight lock scheduling after the specified number of
shared locks is acquired. (See lwlock_shared_limit
parameter description.)
-
Improved multi-host connection handling and failover
by libpq. (See hostorder
and failover_timeout parameter descriptions.)
-
Enabling libpq to forget the entered password,
which allows to prevent reconnections when required by a security policy.
(See reusepass parameter description.)
-
Support for timestamp output in pg_waldump.
- K-nearest neighbors (k-NN) algorithm for B-tree indexes.
(See Section 11.13.)
-
Removing a practically reachable limit on the number of entries
in ACL (access control list, i.e., privileges list) associated
with tables and indexes.
-
The pgpro_stat_wal_activity view that shows
the size of WAL files generated by each process.
-
Verification of unique constraints in B-tree indexes in the
amcheck module.
-
Support for passing named and positional arguments to scripts invoked
by the
\i command in
psql.
-
pg_probackup
enterprise edition, which provides Simple Storage Service (S3) support
for storing data in private clouds,
CFS (Compressed File System) support
for incremental backups, and support for lz4 and zstd
compression algorithms.
-
Lock deduplication that allows to effectively store in memory
and track all exclusive locks held by a standby server's startup process
during WAL replay.
-
Optimized mechanism for working with table metadata, which allows
obtaining information about attributes using the system cache instead of
direct reading from the system catalog.
The following enhancements are also inherited from
Postgres Pro Standard:
-
Better planning speed and accuracy for various query types.
-
Reduced memory consumption in complex queries that involve multiple tables.
-
Displaying planning time in the output of the
auto_explain module.
NUL byte replacement with the specified ASCII code while
loading data using the COPY FROM command. (See
nul_byte_replacement_on_import parameter
description.)
'\u0000' character replacement with the specified
unicode character when calling a function processing JSONB (See
unicode_nul_character_replacement_in_jsonb parameter
description.)
- PTRACK implementation, which enables pg_probackup
to track page changes on the fly when creating incremental backups.
-
Changing the
restore_command
parameter without restarting the server.
-
Advanced authentication policies that provide effective password management and access control.
(See CREATE PROFILE and ALTER ROLE).
-
Built-in data security mechanisms that enable sanitizing an object
by filling it with zeroes before deletion. Zeroing can be done before
purging files in external memory and removing outdated row versions (page vacuum),
freeing RAM, and deleting or overwriting WAL files. (Certified edition only.)
-
Statistics about vacuuming tables, indexes and databases in system
views.
-
Predefined roles, which
allow creating tablespaces and managing profiles without superuser rights.
-
Getting information on crashes of a backend, which is enabled by the
crash_info configuration parameter and controlled
by more of them.
-
Optimized memory consumption during selectivity estimation for each
array element.
Postgres Pro Shardman also includes the
following additional modules and applications:
- aqo extension for adaptive query optimization.
- pgbouncer connection pooler.
- pg_integrity_check
module that calculates and validates checksums for controlled files. (Certified edition only.)
-
pg_proaudit extension that enables detailed
logging of various security events.
- pg_probackup, a backup and recovery manager.
- pgpro_controldata, an application to
display control information of a
PostgreSQL/Postgres Pro Shardman
database cluster and compatibility information for a
cluster and/or server.
- pgpro_pwr extension that enables you
to generate workload reports, which help to discover most resource-intensive activities in your database.
- pgpro_stats extension that tracks execution statistics
of SQL statements, calculates wait event statistics and provides other useful
metrics that are not collected elsewhere in PostgreSQL.
It also provides tracing of application sessions and can create views that emulate
other statistic collecting extensions.
- pg_query_state
module that enables you to get the current state of query execution for a backend.
-
pgvector extension that provides
vector similarity search for Postgres Pro Shardman.
-
pg_wait_sampling
extension for sampling-based statistics of wait events. With this extension,
you can get an insight into the server activity, including the current wait
events for all processes and background workers.
To provide the advanced functionalities and features, Postgres Pro Shardman
imposes more stringent requirements on operating systems supported.
Postgres Pro Shardman runs on the following
operating systems:
-
Ubuntu 20.04/22.04
- Debian 10/11/12
-
Red Hat Enterprise Linux 7/8/9
-
Red OS 7.3/8
-
Alt 9/10/10SP
-
Astra Linux 1.7/1.8/s390
Important
Any reference to Windows or another operating system different from Linux in this documentation
is inapplicable for Postgres Pro Shardman.
Postgres Pro Shardman releases follow PostgreSQL releases, though sometimes occur more frequently.
The Postgres Pro Shardman versioning scheme is based on the PostgreSQL one and has an additional decimal place.