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What is block size in disk?
The logical block size is usually different from the physical block size. The physical block size is usually 512 bytes, which is the size of the smallest block that the disk controller can read or write. Logical block size is set to the page size of the system by default. The recommended logical block size is 8 KB.
How much space does MongoDB need?
Because MongoDB uses a journal file size limit of 100 MB, WiredTiger creates a new journal file approximately every 100 MB of data.
What is the block size in Oracle?
DB_BLOCK_SIZE specifies (in bytes) the size of Oracle database blocks. Typical values are 4096 and 8192 . The value of this parameter must be a multiple of the physical block size at the device level. The value for DB_BLOCK_SIZE in effect at the time you create the database determines the size of the blocks.
Is block size same as sector size?
A sector is the smallest individual reference-able regions on a disk. The block size refers to the allocation size the file system uses. The common options are 512, 1024, 2048, 4096, 8192, 16384, or 32678.
What are block sizes?
Concrete Block (CMU) Sizes
| CMU Size | Nominal Dimensions D x H x L | Actual Dimensions D x H x L |
|---|---|---|
| 4″ CMU Full Block | 4″ x 8″ x 16″ | 3 5/8″ x 7 5/8″ x 15 5/8″ |
| 4″ CMU Half-Block | 4″ x 8″ x 8″ | 3 5/8″ x 7 5/8″ x 7 5/8″ |
| 6″ CMU Full Block | 6″ x 8″ x 16″ | 5 5/8″ x 7 5/8″ x 15 5/8″ |
| 6″ CMU Half-Block | 6″ x 8″ x 8″ | 5 5/8″ x 7 5/8″ x 7 5/8″ |
Can we change db block size?
The DB block size is one of the Oracle system parameters. The default DB block size cannot be changed once the database is created, but multiple DB block sizes can be set up to meet the requirement.
What is Oracle block?
Oracle data blocks are the smallest units of storage that Oracle can use or allocate. In contrast, all data at the physical, operating system level is stored in bytes. Each operating system has what is called a block size. Oracle requests data in multiples of Oracle blocks, not operating system blocks.
How big should a MongoDB working set be?
By default, this collection has a capped size of: 5% of your dbPath volume, with a minimum size of 1GB and maximum size of 50GB. Note: it is critical to have at least one or two days of oplog! The working set: the working set is the frequently accessed data at a specific time.
How does block compression work in MongoDB server?
Block compression can provide significant on-disk storage savings, but data must be uncompressed to be manipulated by the server. Via the filesystem cache, MongoDB automatically uses all free memory that is not used by the WiredTiger cache or by other processes.
How does MongoDB work in the operating system?
The operating system will use the available free memory for filesystem cache, which allows the compressed MongoDB data files to stay in memory. In addition, the operating system will use any free RAM to buffer file system blocks and file system cache.
How to reduce the size of MongoDB indexes?
Index prefix compression: wiredTiger compress both in memory and on disk MongoDB indexes, this greatly reduce the amount of space required to save indices (~40-60% observed here) Oplog size: one things that you should be aware, MongoDB has its own internal journal located in: local.oplog.rs.