CONTROLFILE BACKUP TO TRACE REFERS PDB DATAFILE OFFLINE IN CDB$ROOT CONTEXT
备份和灾难恢复应用感知装载可能会失败。
12.1.0.2
23019710
RMAN LIST BACKUP SUMMARY 失败，并显示以下任一错误：
ORA-01507: database not mounted
ORA-01219: database or pluggable database not open:
queries allowed on fixed
ORA-00972: identifier is too long
ORA-01589: must use RESETLOGS or NORESETLOGS option
for database open
ORA-01426: numeric overflow
ORA-01152: file 3 was not restored from a sufficiently
old backup
ORA-01110: data file 3:
ORA-01109: database not open
ORA-01034: ORACLE not available
在 Backup and DR 备份期间，Backup and DR 代理会查询 dba_free_space Oracle 元数据表，以确定数据库的已分配空间和可用空间。有时，对 dba_free_space 的 SQL 查询会变得非常耗费资源。这是 Oracle 已知问题文档 ID 271169.1（对 DBA_FREE_SPACE 的查询速度较慢）。在挂起的系统上，可以通过从命令行运行 ps -ef | grep -i dbFreeSize.sql 来观察到这一点。
Oracle 建议从数据库中清除回收站：
以 sysdba 身份登录数据库：
```sh
sqlplus / as sysdba
SQL>purge dba_recyclebin;
SQL>exit;
```
最好对固定对象运行统计信息。
此过程可能需要几分钟的时间。
以 sysdba 身份登录数据库：
```sh
sqlplus / as sysdba
SQL>exec dbms_stats.GATHER_FIXED_OBJECTS_STATS
SQL>exit;
```
另请参阅 ASM 可伸缩性和限制（来自 Oracle 文档 ID 370921.1）。
max_string_size=extended 参数对应用感知装载、恢复和切换恢复的影响
如果源数据库中的 max_string_size init 参数设置为 extended，则在更改此参数之前拍摄的数据库备份映像的感知应用装载或恢复，以及使用在此更改之后拍摄的日志备份进行前滚，将失败并显示以下错误：ORA-14694: database must be in UPGRADE mode to begin MAX_STRING_SIZE migration
[[["易于理解","easyToUnderstand","thumb-up"],["解决了我的问题","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["很难理解","hardToUnderstand","thumb-down"],["信息或示例代码不正确","incorrectInformationOrSampleCode","thumb-down"],["没有我需要的信息/示例","missingTheInformationSamplesINeed","thumb-down"],["翻译问题","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["最后更新时间 (UTC)：2025-09-04。"],[[["\u003cp\u003eSpecific Oracle patches are necessary for optimal performance with Backup and DR, especially for versions 11.2.0.1 through 19c, addressing issues like memory leaks, block header errors, and restore failures.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003edba_free_space\u003c/code\u003e table queries can be slow, requiring a purge of the recycle bin and running statistics on fixed objects to enhance database backup and recovery efficiency.\u003c/p\u003e\n"],["\u003cp\u003eSetting the \u003ccode\u003emax_string_size\u003c/code\u003e parameter to \u003ccode\u003eextended\u003c/code\u003e requires a new full database backup to ensure successful application-aware mounts or restores.\u003c/p\u003e\n"],["\u003cp\u003eFor Windows environments, \u003ccode\u003eSQLNET.AUTHENTICATION_SERVICES\u003c/code\u003e must be set to \u003ccode\u003e(nts)\u003c/code\u003e to avoid connection failures and ensure the proper execution of restore jobs.\u003c/p\u003e\n"],["\u003cp\u003eASM storage limits vary based on Oracle versions, Exadata usage, and disk group attributes, with maximums ranging from 2 TB to 32 PB per ASM disk, and up to 320 EB for the storage system, depending on configuration.\u003c/p\u003e\n"]]],[],null,["# Oracle patches and known issues\n\nThese are the Oracle patches that must be applied for best results with Oracle\nin Backup and DR.\n\nKnown Oracle issues\n===================\n\nFor best performance, be sure to review and address these Oracle known issues.\n\nQueries on DBA_FREE_SPACE are slow (Doc ID 271169.1)\n----------------------------------------------------\n\nDuring Backup and DR backup, the Backup and DR agent queries the\n**`dba_free_space`** Oracle metadata table to determine the\ndatabase allocated and free space. Sometimes the sql queries to\ndba_free_space become costly. This is Oracle known issue\nDoc ID 271169.1 (Queries on `DBA_FREE_SPACE` are slow).\nThis can be observed on a hung system by running\n`ps -ef | grep -i dbFreeSize.sql` from the command line.\n\nOracle recommends to purge the recycle bin from the database:\n\n1. Login to the database as sysdba:\n\n ```sh\n sqlplus / as sysdba\n SQL\u003epurge dba_recyclebin;\n SQL\u003eexit;\n ```\n\n2. It is a good idea to run the statistics on fixed objects.\n This can take a few minutes.\n\n Log into the database as sysdba: \n\n ```sh\n sqlplus / as sysdba\n SQL\u003eexec dbms_stats.GATHER_FIXED_OBJECTS_STATS\n SQL\u003eexit;\n ```\n\nSee also ASM scalability and limits (from Oracle Doc ID 370921.1).\n\nImpact of `max_string_size=extended` parameter on application aware mounts, restore \\& switch restore\n-----------------------------------------------------------------------------------------------------\n\nIf the `max_string_size init` parameter is set to `extended` in the source\ndatabase, then an app-aware mount or restore of the DB backup image taken before\nthis parameter change along with roll-forward using log backups taken after this\nchange fails with the error: **ORA-14694: database must be in UPGRADE mode to begin `MAX_STRING_SIZE` migration**\n\n**Solution**\nIf you set the `max_string_size init` parameter to `extended` in the source\ndatabase, run a new on-demand level 1 (full) database backup job [1](/backup-disaster-recovery/docs/monitor-reports/monitor-jobs#run) and use the\nnew image for app-aware mount or restore operations.\n\n`SQLNET.AUTHENTICATION_SERVICES` must be set to nts in a Windows environment\n----------------------------------------------------------------------------\n\nOn Windows, Oracle database sqlnet.ora is configured with\n`SQLNET.AUTHENTICATION_SERVICES` = (none). This restricts the database connection\nto using Windows operating system authentication. This requires a valid\ndatabase username and password to connect to the database, without which restore\njobs can fail.\n\nSolution: Set `SQLNET.AUTHENTICATION_SERVICES` = (nts)\n\nASM scalability and limits (from Oracle Doc ID 370921.1)\n--------------------------------------------------------\n\nThis depends on:\n\n- [Oracle Database, Enterprise Edition](#enterprise-edition)\n\n- [Oracle Database12c](#db-12c)\n\n- [With Oracle Exadata Storage](#exadata)\n\n- [Without Exadata Storage, COMPATIBLE.ASM or COMPATIBLE.RDBMS disk group attribute \\\u003c 12.1](#asm-or-rdbms)\n\n- [Without Exadata Storage, COMPATIBLE.ASM and COMPATIBLE.RDBMS disk group attributes \\\u003e 12.1](#asm-and-rdbms)\n\n**Oracle Database, Enterprise Edition**\n\nFor Oracle Database, Enterprise Edition, Versions 10.1.0.2\nto 11.1.0.7 and 11.2.0.3, ASM imposes the following limits:\n\n- 63 disk groups in a storage system\n\n- 10,000 ASM disks in a storage system\n\n- 2 terabyte maximum storage for each ASM disk (the Bug 6453944 allowed larger sizes,\n but that led to problems, see Note 736891.1 \"ORA-15196 WITH ASM DISKS\n LARGER THAN 2TB\")\n\n- 40 exabyte maximum storage for each storage system\n\n- 1 million files for each disk group\n\n- 2.4 terabyte maximum storage for each file\n\n**Oracle Database12c**\n\nFor Oracle Database12c, ASM imposes the following limits:\n\n- 511 disk groups in a storage system for Oracle Database 12c Release 1 or\n later\n\n- 10,000 Oracle ASM disks in a storage system\n\n- 1 million files for each disk group\n\n**With Oracle Exadata Storage**\n\nWith all Oracle Exadata Storage, Oracle ASM has the\nfollowing storage limits:\n\n- 4 PB maximum storage for each Oracle ASM disk with the AU size equal to 1 MB\n\n- 8 PB maximum storage for each Oracle ASM disk with the AU size equal to 2 MB\n\n- 16 PB maximum storage for each Oracle ASM disk with the AU size equal to 4 MB\n\n- 32 PB maximum storage for each Oracle ASM disk with the AU size equal to 8 MB\n\n- 320 EB maximum for the storage system\n\n**Without Exadata Storage, COMPATIBLE.ASM or COMPATIBLE.RDBMS disk group attribute \\\u003c 12.1**\n\nWithout any Oracle Exadata Storage, Oracle ASM has\nthe following storage limits if the COMPATIBLE.ASM or COMPATIBLE.RDBMS\ndisk group attribute is set to less than 12.1:\n\n- 2 terabytes (TB) maximum storage for each Oracle ASM disk\n\n- 20 petabytes (PB) maximum for the storage system\n\n**Without Exadata Storage, COMPATIBLE.ASM and COMPATIBLE.RDBMS disk group attributes \\\u003e 12.1**\n\nWithout any Oracle Exadata Storage, Oracle ASM has\nthe following storage limits if the COMPATIBLE.ASM and COMPATIBLE.RDBMS\ndisk group attributes are set to 12.1 or greater:\n\n- 4 PB maximum storage for each Oracle ASM disk with the allocation unit (AU)\n size equal to 1 MB\n\n- 8 PB maximum storage for each Oracle ASM disk with the AU size equal to 2 MB\n\n- 16 PB maximum storage for each Oracle ASM disk with the AU size equal to 4 MB\n\n- 32 PB maximum storage for each Oracle ASM disk with the AU size equal to 8 MB\n\n- 320 exabytes (EB) maximum for the storage system\n\nThe Oracle DBA Guide\n--------------------\n\n- [Backup and DR for Oracle databases](/backup-disaster-recovery/docs/concepts/oracle-intro)\n- [Prerequisites for protecting an Oracle database](/backup-disaster-recovery/docs/configuration/oracle-db-prerequisites)\n- [Oracle patches and known issues](/backup-disaster-recovery/docs/concepts/oracle-patches-known-issues)\n- [Prepare Oracle databases for protection](/backup-disaster-recovery/docs/configuration/oracle-db-prepare)\n- [Discover and protect an Oracle database](/backup-disaster-recovery/docs/configuration/discover-and-protect-oracle)\n- [Details and settings for Oracle databases](/backup-disaster-recovery/docs/create-plan/oracle-advanced-settings)\n- [Use dNFS with Backup and DR](/backup-disaster-recovery/docs/configuration/oracle-dnfs)\n- [Protect a discovered Oracle database](/backup-disaster-recovery/docs/backup/oracle-db-protect)\n- [Mount an Oracle database as a standard mount](/backup-disaster-recovery/docs/access-data/oracle-mount)\n- [Create an instant virtual copy of an Oracle database](/backup-disaster-recovery/docs/access-data/oracle-mount-virtualdb)\n- [Restore and recover an Oracle database](/backup-disaster-recovery/docs/restore-data/restore-oracle)\n- [Instant recovery of an Oracle database using Mount and Migrate](/backup-disaster-recovery/docs/restore-data/oracle-mm)\n- [Provision an environment with a Backup and DR workflow](/backup-disaster-recovery/docs/access-data/create-workflow-oracle)"]]
