Resolve Database Issues

Learn how to diagnose and resolve database issues, including detected problems, resource contention, database delays, internal errors, memory issues, and database performance problems using Oracle Autonomous Health Framework (AHF).

Resolve Problems AHF has Detected

To investigate problems detected by AHF Insights, run tfactl diagcollect as the Oracle user on the affected machine, transfer and extract the diagnostic archive, open its embedded index.html, and select Detected Problems. The page provides each problem’s description, reason, root cause, supporting evidence, and resolution steps; the section appears only when problems are detected. Typical causes include configuration issues, resource bottlenecks, network or I/O failures, memory growth, contention, blocked processes, insufficient redo or buffers, and storage errors.

Resolve Noisy Neighbor Issues

AHF Balance analyzes historical CPU consumption and Database Resource Manager settings from Enterprise Manager to identify CPU-based noisy-neighbor exposure and recommend CPU_COUNT values. It supports partitioned clusters, where CPU capacity is dedicated, and risk-management configurations for over-provisioned clusters. Reports are available at cluster, fleet, and database levels and show current, disaster, and recommended exposure and impact scenarios, including enhanced recommendations for standby databases that may become primary during a disaster. Configure the Enterprise Manager repository connection with ahf configuration set --type impact, then create fleet or cluster analyses with ahf analysis create; reports use hourly EM data, normally retained for 32 days.

Resolving Database and Database Instance Delays

Blocker Resolver is an autonomous DIA0 database task that detects sessions waiting on resources, analyzes whether waits represent potential delays, verifies them after a threshold, and terminates the blocking session or process when necessary. Its sensitivity can be set to Normal or High with DBMS_BLOCKER_RESOLVER, while trace-file size and count are configurable through base_file_size_limit and base_file_set_count; DBMS_HANG_MANAGER is deprecated in Oracle AI Database 26ai. Resolutions are recorded as ADR incidents with code ORA-32701, with diagnostics in DIA0 trace files and alert logs. The cluster resource activity log and crsctl query calog provide hierarchical, activity-ID-based details for Oracle Clusterware resource failures and their causes.

Resolving ORA-00600 Internal Error Codes

ORA-00600 is a generic low-level internal error, usually indicating an unexpected condition or software bug, with arguments that help identify the failing function and diagnostic context. Review the database alert log and referenced trace file, then collect an SRDC from the affected machine with tfactl diagcollect -srdc ORA-00600 as the Oracle user. Upload the resulting TFA package to the My Oracle Support ORA-00600 troubleshooting tool to obtain matching recommendations and possible bug or release-update information; if no resolution is found, create a Service Request and provide the requested product, version, support, operating-system, and severity details.

Resolving ORA-04031 unable to allocate bytes of shared memory Error Codes

ORA-04031 occurs when a process cannot allocate required shared memory, commonly because memory parameters are too low, automatic tuning has problems, application design causes fragmentation, or a bug or memory leak exists. Collect an SRDC with tfactl diagcollect -srdc ORA-04031, selecting the relevant time and database, then upload the affected-node archive to the My Oracle Support ORA-04031 troubleshooting tool for diagnostic recommendations. If the tool does not resolve the issue, create a Service Request, complete the product, version, support identifier, operating system, and severity fields, and submit the diagnostic collection for Oracle Support review.

Resolving ORA-07445 exception encountered - core dump

ORA-07445 indicates an operating-system exception in an Oracle process that should generate a core file; common causes include bad data, severe misconfiguration, or a software bug. Run tfactl diagcollect -srdc ORA-07445 as the Oracle user on the affected machine, specify the relevant time and database, and use the resulting TFA package with the My Oracle Support ORA-07445 troubleshooting tool. The tool analyzes the collection and recommends applicable knowledge documents, bug fixes, or release updates. If no solution is identified, create a Service Request, provide the requested environment and severity information, and attach the diagnostic collection.

Resolving ORA-04030 out of process memory when trying to allocate

ORA-04030 occurs when an Oracle or client process exhausts operating-system memory or its available PGA allocation. Resolution may involve increasing physical memory, adjusting PGA limits, reducing resource consumption, correcting operating-system limits, or addressing a memory leak. Generate an SRDC with tfactl diagcollect -srdc ORA-04030, select the relevant event and database, and upload the affected-node archive to the My Oracle Support ORA-04030 troubleshooting tool. Review its recommendations and related bug or release-update information; if necessary, create a Service Request with the required product, version, support, operating-system, and severity details so Oracle Support can analyze the collection.

Database Performance Tuning

Oracle database performance tuning begins by determining whether the issue is database-wide, such as CPU, I/O, memory, network, process, configuration, hang, or bug related, or query-specific, such as inefficient SQL, missing indexes, stale statistics, or changed execution plans. Collect diagnostics with tfactl diagcollect -srdc dbperf -database <database_name>, including bad and comparable good periods when possible, then use AHF Insights to review best-practice deviations, anomalies, resource bottlenecks, operating-system metrics, and embedded PerfHub, AWR, and ADDM reports. Use ASH and ADDM findings to identify CPU-bound workloads and expensive SQL, configure AHF Balance against Enterprise Manager to investigate noisy neighbors when relevant, and create a Service Request with the collection if further assistance is required.
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