What Oracle Buffer Cache?

1. What is the Buffer
Cache of Oracle

2. Buffer cache is a portion of
memory in the SGA that stores
copies of data blocks from disk
for quick access.
It acts as a temporary storage
area for frequently accessed
data, reducing the need for
disk I/O.
The buffer cache is managed
by the database buffer cache
manager.
DEFINITION OF BUFFER CACHE

3. PURPOSE OF BUFFER CACHE
The main purpose of the
buffer cache is to improve
database performance by
reducing physical I/O
operations.
It helps in minimising the
time required to read data
from disk, as frequently
accessed data is readily
available in memory.
Buffer cache also aids in
maintaining data
consistency and reducing
contention for data blocks.

4. Buffer cache plays a crucial role in enhancing the overall performance and scalability of Oracle
databases.
It contributes to efficient data retrieval, which is vital for supporting high transaction volumes and
concurrent user access.
The buffer cache significantly impacts the response time of database queries and transactions.
IMPORTANCE OF BUFFER CACHE IN ORACLE

5. Stores frequently accessed
data blocks in memory
Reduces the need to read from
disk for commonly used data
Improves data retrieval speed
CACHING MECHANISM FOR DATA BLOCKS

6. Minimises the response time for queries
Enhances overall system performance
Optimises resource utilisation
IMPROVEMENT OF DATABASE
PERFORMANCE

7. Lowers the amount of data
read from and written to disk
Decreases disk contention and
improves throughput
Diminishes the impact of slow
disk access
REDUCTION OF DISK I/ O OPERATIONS

8. Oracle automatically manages
the buffer cache by default
Manual management involves
setting specific parameters
DBAs can allocate and
deallocate memory for the
buffer cache
AUTOMATIC AND MANUAL MANAGEMENT

9. Buffer Cache Advisory helps in
predicting the impact of cache
size changes
It provides recommendations
for optimal cache size based on
workload
DBAs can use the advisory to
make informed decisions about
cache size
BUFFER CACHE ADVISORY

10. DBAs can monitor cache hit ratios to assess
cache efficiency
Tuning involves adjusting cache size and
using multiple block sizes
Regular monitoring and tuning ensure
optimal performance
MONITORING AND TUNING
BUFFER CACHE

11. Allocate 75% of available
memory to buffer cache for
optimal performance.
Regularly monitor cache hit
ratio to determine if the size is
adequate.
Consider increasing buffer
cache size if cache hit ratio is
consistently low.
OPTIMIZING BUFFER CACHE SIZE

12. IDENTIFYING HOT BLOCKS
Use Automatic Workload Repository (AWR) reports to identify frequently accessed
blocks.
Leverage Oracle's performance monitoring tools to pinpoint hot blocks.
Implement partitioning or pinning for frequently accessed data to reduce contention.

13. Divide buffer cache into multiple sub-caches for different types of data.
Utilize partitioning to isolate critical data and reduce contention.
Consider using Automatic Data Optimization (ADO) to automate partitioning based on usage
patterns.
IMPLEMENTING BUFFER CACHE PARTITIONING

14. SUMMARY OF BUFFER CACHE BENEFITS
Improves database performance by reducing physical I/O operations
Enhances data retrieval speed for frequently accessed data
Minimises disk access, leading to faster query execution

15. RECOMMENDATIONS FOR EFFECTIVE BUFFER CACHE USAGE
Regularly monitor buffer cache hit ratio for optimal performance
Allocate sufficient memory to buffer cache based on workload
Consider using multiple buffer pools for different types of data

16. Integration of machine learning for intelligent cache management
Enhanced support for non-volatile memory as cache storage
Incorporation of advanced algorithms for adaptive caching
FUTURE DEVELOPMENTS IN BUFFER CACHE TECHNOLOGY

17. Thanks for Watching
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