This topic describes the feature updates of PolarDB-O.

V1.1.2

Feature Description
New features
  • Allows you to specify an alias for a table or subquery in the Pivot syntax.
  • Supports the ROWID pseudo column, ROWIDTOCHAR and CHARTOROWID functions.
  • Supports LNNVL, DUMP, SYS_CONTEXT, USERENV, TZ_OFFSET, and VSIZE functions.
  • Supports DBMS_JOB and DBMS_SCHEDULER to help you maintain and manage jobs.
  • Allows to write temporary tables to local storage. This improves the read and write performance of temporary tables.
  • Allows accounts with the polar_superuser privilege to perform logical replication of events that are captured by the event trigger.
  • Supports requests from custom resource isolation groups.
Performance optimization Optimizes the recovery process after a crash. This reduces the amount of time that is required for recovery from certain extreme cases.
Fixed issues Accounts with the polar_superuser privilege cannot use the index advisor.
Ganos 2.8
  • The following enhancements are added to access raster metadata:
    • The ST_XMin function is added to obtain the minimum value in the X direction of raster data. For more information, see ST_XMin.
    • The ST_YMin function is added to obtain the minimum value in the Y direction of raster data. For more information, see ST_YMin.
    • The ST_XMax function is added to obtain the maximum value in the X direction of raster data. For more information, see ST_XMax.
    • The ST_YMax function is added to obtain the maximum value in the Y direction of raster data. For more information, see ST_YMax.
    • The ST_ChunkHeight function is added to obtain the height of a raster tile. For more information, see ST_ChunkHeight.
    • The ST_ChunkWidth function is added to obtain the width of a raster tile. For more information, see ST_ChunkWidth.
    • The ST_ChunkBands function is added to obtain the number of bands in a raster tile. For more information, see ST_ChunkBands.
  • The ST_SrFromEsriWkt function is added to convert the format of a spatial reference string from Esri to Open Geospatial Consortium (OGC). For more information, see ST_SrFromEsriWkt.
  • Raster data files can be compressed by the Zstandard (zstd) or Snappy compression tool.
  • Point cloud files can be copied in binary mode.
  • The PROJ_LIB and GDAL_DATA environment variables can be configured, and relevant data can be deployed.
  • The database breakdown issue that is caused by an invalid Object Storage Service (OSS) path is fixed.
  • After the raster data is imported to databases, the spatial reference identifiers (SRIDs) of some raster data are inconsistent with original SRIDs.

V1.1.1

Feature Description
Built-in functions The NVL2 function is added. This function returns the value of the second or third parameter based on whether the value of the first parameter is NULL or an empty string.
Plug-ins
  • The polar_proxy_utils plug-in is added to manage proxy-related features. This plug-in allows you to configure read-only Universal Disk Format (UDF) files and read-only tables. This plug-in also allows you to use a cluster endpoint to route requests to read-only nodes in the cluster to access read-only UDF files and read-only tables.
  • The polar_resource_group plug-in is added to customize resource groups. You can isolate resources such as CPU and memory on a per-user, per-database, or per-session basis.
Performance optimization
  • The compute nodes of databases are decoupled from file systems so that you can independently perform operations and maintenance (O&M) on file systems. This improves the reliability and availability of databases.
  • The snapshot of the active transaction list is replaced with a commit sequence number (CSN). Each CSN is a monotonically increasing identifier. This improves the transaction processing performance of databases.
  • The execution plan is optimized to avoid the use of obsolete statistics.
Fixed issues
  • A database process failure occurs when the TimescaleDB plug-in fails to request memory.
  • The input/output (I/O) monitoring feature does not provide data statistics after a process exits.
  • A null pointer exception may occur after lock_debug is enabled.
  • The pg_cron plug-in becomes unavailable in specific cases.
  • The known issue of distributed shared memory (DSM) deadlock in PostgreSQL Community Edition.
  • The number of connections to a PolarDB-O database exceeds the upper limit.

V1.1.0

Feature Description
Built-in functions
  • The TO_SINGLE_BYTE function is added to convert multi-byte characters in a string to single-byte characters. For more information, see TO_SINGLE_BYTE and TO_MULTI_BYTE functions.
  • The TO_MULTI_BYTE function is added to convert single-byte characters in a string to multi-byte characters. For more information, see TO_SINGLE_BYTE and TO_MULTI_BYTE functions.
  • The REGEXP_LIKE function is added. You can use this function in the similar way as LIKE. The REGEXP_LIKE function complies with the POSIX regular expression.
  • The RATIO_TO_REPORT function is added to calculate the ratio of a value to the sum of a set of values.
  • The ROUND function is optimized to support the Interval data type. The returned values are measured in days. For more information, see ROUND.
Built-in packages and procedure functions
  • The DBMS_UTILITY.FORMAT_ERROR_STACK function (macro) is added to return the error stack.
  • The UTL_I18N.ESCAPE_REFERENCE and UTL_I18N.UNESCAPE_REFERENCE functions are added. These functions provide escape and unescape mechanisms for HTML or XML characters.
Built-in views The polar_stat_activity view is optimized and the wait_info and wait_time columns are added. The wait_info column displays the object for which the current process is waiting, and the wait_time column displays the amount of time that the process needs to wait. If the object is a process, the process identifier (PID) is displayed. If the object is a file, the file descriptor (FD) is displayed.
Data query languages (DQL) and data manipulation language (DML) The INSERT ALL syntax is supported, which allows you to insert data into multiple tables at a time.
Plug-ins
  • The polar_concurrency_control plug-in is added to set a concurrency limit on transaction executions, SQL queries, stored procedures, and DML operations. You can customize large queries and set a concurrency limit on large queries to improve the execution efficiency in high concurrency scenarios.
  • The pldebugger plug-in is added to debug on-premises stored procedures. You can use the client pgAdmin 4 4.19 or later.
  • The oss_fdw plug-in is added to support external tables of Alibaba Cloud OSS. You can use OSS external tables to write data of PolarDB-O databases to OSS, or load data from OSS to PolarDB-O databases. You can use multiple external tables in parallel or compress data during imports and exports. This improves the efficiency of data import and export. You can also use this feature to separate hot data and cold data that are stored in a wide range of storage media. For more information, see Read and write external data files by using oss_fdw.
Performance optimization The pre-extension feature is added. This feature automatically adds additional index pages when index pages are insufficient for new indexes. This improves the execution efficiency when data is inserted into an table with indexes.
Ganos 2.7
  • MD5 functions are added for spatial raster objects. You can invoke these functions to check data consistency and remove duplicates.
    • The ST_MD5Sum function is added to obtain the MD5 hash value of a raster object. For more information, see ST_MD5Sum.
    • The ST_SetMD5Sum function is added to set the MD5 hash value of a raster object. For more information, see ST_SetMD5Sum.
  • OSS authentication functions are added for spatial raster objects:
    • The ST_AKId function is added to obtain the AccessKey ID of a raster object stored in OSS. For more information, see ST_AKId.
    • The ST_SetAccessKey function is added to set the AccessKey ID and the AccessKey secret of a raster object stored in OSS. For more information, see ST_SetAccessKey.
    • The ST_SetAKId function is added to set the AccessKey ID of a raster object stored in OSS. For more information, see ST_SetAKId.
    • The ST_SetAKSecret function is added to set the AccessKey secret of a raster object stored in OSS. For more information, see ST_SetAKSecret.
  • Metadata functions are added for spatial rasters:
    • The ST_ScaleX function is added to obtain the pixel width of a raster object on the X-axis of the spatial reference system. For more information, see ST_ScaleX.
    • The ST_ScaleY function is added to obtain the pixel width of a raster object on the Y-axis of the spatial reference system. For more information, see ST_ScaleY.
    • The ST_SetScale function is added to set the pixel width of a raster object in the spatial reference system. For more information, see ST_ScaleY.
    • The ST_SkewX function is added to obtain the skew of a raster object on the X-axis of the spatial reference system. For more information, see ST_SkewX.
    • The ST_SkewY function is added to obtain the skew of a raster object on the Y-axis of the spatial reference system. For more information, see ST_SkewY.
    • The ST_SetSkew function is added to set the skew of a raster object in the spatial reference system. For more information, see ST_SetSkew.
    • The ST_UpperLeftX function is added to obtain the upper-left X-coordinate of a raster object in the spatial reference system. For more information, see ST_UpperLeftX.
    • The ST_UpperLeftY function is added to obtain the upper-left Y-coordinate of a raster object in the spatial reference system. For more information, see ST_UpperLeftY.
    • The ST_SetUpperLeft function is added to set the upper-left coordinates of a raster object in the spatial reference system. For more information, see ST_SetUpperLeft.
    • The ST_PixelWidth function is added to obtain the pixel width of a raster object in the spatial reference system. For more information, see ST_PixelWidth.
    • The ST_PixelHeight function is added to obtain the pixel height of a raster object in the spatial reference system. For more information, see ST_PixelHeight.
  • The issue of extension upgrade failures caused by aggregate functions is fixed.