org.rocksdb

Interface ColumnFamilyOptionsInterface

All Known Implementing Classes:

ColumnFamilyOptions, Options

public interface ColumnFamilyOptionsInterface

Field Summary

Fields

Modifier and Type	Field and Description
static long	DEFAULT_COMPACTION_MEMTABLE_MEMORY_BUDGET Default memtable memory budget used with the following methods: optimizeLevelStyleCompaction() optimizeUniversalStyleCompaction()

Method Summary

Methods

Modifier and Type	Method and Description
int	bloomLocality() Control locality of bloom filter probes to improve cache miss rate.
CompactionStyle	compactionStyle() Compaction style for DB.
java.util.List<CompressionType>	compressionPerLevel() Return the currently set CompressionType per instances.
CompressionType	compressionType() Compress blocks using the specified compression algorithm.
double	hardRateLimit() Puts are delayed 1ms at a time when any level has a compaction score that exceeds hard_rate_limit.
boolean	inplaceUpdateSupport() Allows thread-safe inplace updates.
boolean	levelCompactionDynamicLevelBytes() Return if LevelCompactionDynamicLevelBytes is enabled.
int	levelZeroFileNumCompactionTrigger() The number of files in level 0 to trigger compaction from level-0 to level-1.
int	levelZeroSlowdownWritesTrigger() Soft limit on the number of level-0 files.
int	levelZeroStopWritesTrigger() Maximum number of level-0 files.
double	maxBytesForLevelMultiplier() The ratio between the total size of level-(L+1) files and the total size of level-L files for all L.
long	maxCompactionBytes() Control maximum size of each compaction (not guaranteed)
int	maxMemCompactionLevel() Deprecated.
long	maxTableFilesSizeFIFO() FIFO compaction option.
java.lang.String	memTableFactoryName() Returns the name of the current mem table representation.
int	minPartialMergeOperands() The number of partial merge operands to accumulate before partial merge will be performed.
int	minWriteBufferNumberToMerge() The minimum number of write buffers that will be merged together before writing to storage.
int	numLevels() If level-styled compaction is used, then this number determines the total number of levels.
boolean	optimizeFiltersForHits() Returns the current state of the optimize_filters_for_hits setting.
ColumnFamilyOptionsInterface	optimizeForPointLookup(long blockCacheSizeMb) Use this if you don't need to keep the data sorted, i.e.
ColumnFamilyOptionsInterface	optimizeLevelStyleCompaction() Default values for some parameters in ColumnFamilyOptions are not optimized for heavy workloads and big datasets, which means you might observe write stalls under some conditions.
java.lang.Object	optimizeLevelStyleCompaction(long memtableMemoryBudget) Default values for some parameters in ColumnFamilyOptions are not optimized for heavy workloads and big datasets, which means you might observe write stalls under some conditions.
java.lang.Object	optimizeUniversalStyleCompaction() Default values for some parameters in ColumnFamilyOptions are not optimized for heavy workloads and big datasets, which means you might observe write stalls under some conditions.
java.lang.Object	optimizeUniversalStyleCompaction(long memtableMemoryBudget) Default values for some parameters in ColumnFamilyOptions are not optimized for heavy workloads and big datasets, which means you might observe write stalls under some conditions.
boolean	purgeRedundantKvsWhileFlush() Purge duplicate/deleted keys when a memtable is flushed to storage.
int	rateLimitDelayMaxMilliseconds() The maximum time interval a put will be stalled when hard_rate_limit is enforced.
java.lang.Object	setBloomLocality(int bloomLocality) Control locality of bloom filter probes to improve cache miss rate.
java.lang.Object	setCompactionStyle(CompactionStyle compactionStyle) Set compaction style for DB.
java.lang.Object	setComparator(AbstractComparator<? extends AbstractSlice<?>> comparator) Use the specified comparator for key ordering.
java.lang.Object	setComparator(BuiltinComparator builtinComparator) Set BuiltinComparator to be used with RocksDB.
java.lang.Object	setCompressionPerLevel(java.util.List<CompressionType> compressionLevels) Different levels can have different compression policies.
java.lang.Object	setCompressionType(CompressionType compressionType) Compress blocks using the specified compression algorithm.
java.lang.Object	setHardRateLimit(double hardRateLimit) Puts are delayed 1ms at a time when any level has a compaction score that exceeds hard_rate_limit.
java.lang.Object	setInplaceUpdateSupport(boolean inplaceUpdateSupport) Allows thread-safe inplace updates.
java.lang.Object	setLevelCompactionDynamicLevelBytes(boolean enableLevelCompactionDynamicLevelBytes) If true, RocksDB will pick target size of each level dynamically.
java.lang.Object	setLevelZeroFileNumCompactionTrigger(int numFiles) Number of files to trigger level-0 compaction.
java.lang.Object	setLevelZeroSlowdownWritesTrigger(int numFiles) Soft limit on number of level-0 files.
java.lang.Object	setLevelZeroStopWritesTrigger(int numFiles) Maximum number of level-0 files.
java.lang.Object	setMaxBytesForLevelMultiplier(double multiplier) The ratio between the total size of level-(L+1) files and the total size of level-L files for all L.
java.lang.Object	setMaxCompactionBytes(long maxCompactionBytes) Maximum size of each compaction (not guarantee)
java.lang.Object	setMaxMemCompactionLevel(int maxMemCompactionLevel) Deprecated.
java.lang.Object	setMaxTableFilesSizeFIFO(long maxTableFilesSize) FIFO compaction option.
java.lang.Object	setMemTableConfig(MemTableConfig config) Set the config for mem-table.
java.lang.Object	setMergeOperator(MergeOperator mergeOperator) Set the merge operator to be used for merging two different key/value pairs that share the same key.
java.lang.Object	setMergeOperatorName(java.lang.String name) Set the merge operator to be used for merging two merge operands of the same key.
java.lang.Object	setMinPartialMergeOperands(int minPartialMergeOperands) The number of partial merge operands to accumulate before partial merge will be performed.
java.lang.Object	setMinWriteBufferNumberToMerge(int minWriteBufferNumberToMerge) The minimum number of write buffers that will be merged together before writing to storage.
java.lang.Object	setNumLevels(int numLevels) Set the number of levels for this database If level-styled compaction is used, then this number determines the total number of levels.
java.lang.Object	setOptimizeFiltersForHits(boolean optimizeFiltersForHits) This flag specifies that the implementation should optimize the filters mainly for cases where keys are found rather than also optimize for keys missed.
java.lang.Object	setPurgeRedundantKvsWhileFlush(boolean purgeRedundantKvsWhileFlush) Purge duplicate/deleted keys when a memtable is flushed to storage.
java.lang.Object	setRateLimitDelayMaxMilliseconds(int rateLimitDelayMaxMilliseconds) The maximum time interval a put will be stalled when hard_rate_limit is enforced.
java.lang.Object	setSoftRateLimit(double softRateLimit) Puts are delayed 0-1 ms when any level has a compaction score that exceeds soft_rate_limit.
java.lang.Object	setTableFormatConfig(TableFormatConfig config) Set the config for table format.
double	softRateLimit() Puts are delayed 0-1 ms when any level has a compaction score that exceeds soft_rate_limit.
java.lang.String	tableFactoryName()
java.lang.Object	useCappedPrefixExtractor(int n) Same as fixed length prefix extractor, except that when slice is shorter than the fixed length, it will use the full key.
java.lang.Object	useFixedLengthPrefixExtractor(int n) This prefix-extractor uses the first n bytes of a key as its prefix.

Field Detail

DEFAULT_COMPACTION_MEMTABLE_MEMORY_BUDGET

static final long DEFAULT_COMPACTION_MEMTABLE_MEMORY_BUDGET

Default memtable memory budget used with the following methods:

1. optimizeLevelStyleCompaction()
2. optimizeUniversalStyleCompaction()

See Also:

Constant Field Values

Method Detail

optimizeForPointLookup

ColumnFamilyOptionsInterface optimizeForPointLookup(long blockCacheSizeMb)

Use this if you don't need to keep the data sorted, i.e. you'll never use an iterator, only Put() and Get() API calls

Parameters:

blockCacheSizeMb - Block cache size in MB

Returns:

the instance of the current Object.

optimizeLevelStyleCompaction

ColumnFamilyOptionsInterface optimizeLevelStyleCompaction()

Default values for some parameters in ColumnFamilyOptions are not optimized for heavy workloads and big datasets, which means you might observe write stalls under some conditions. As a starting point for tuning RocksDB options, use the following for level style compaction.

Make sure to also call IncreaseParallelism(), which will provide the biggest performance gains.

Note: we might use more memory than memtable_memory_budget during high write rate period

Returns:

the instance of the current Object.

optimizeLevelStyleCompaction

java.lang.Object optimizeLevelStyleCompaction(long memtableMemoryBudget)

Default values for some parameters in ColumnFamilyOptions are not optimized for heavy workloads and big datasets, which means you might observe write stalls under some conditions. As a starting point for tuning RocksDB options, use the following for level style compaction.

Make sure to also call IncreaseParallelism(), which will provide the biggest performance gains.

Note: we might use more memory than memtable_memory_budget during high write rate period

Parameters:

memtableMemoryBudget - memory budget in bytes

Returns:

the instance of the current Object.

optimizeUniversalStyleCompaction

java.lang.Object optimizeUniversalStyleCompaction()

Default values for some parameters in ColumnFamilyOptions are not optimized for heavy workloads and big datasets, which means you might observe write stalls under some conditions. As a starting point for tuning RocksDB options, use the following for universal style compaction.

Universal style compaction is focused on reducing Write Amplification Factor for big data sets, but increases Space Amplification.

Make sure to also call IncreaseParallelism(), which will provide the biggest performance gains.

Note: we might use more memory than memtable_memory_budget during high write rate period

Returns:

the instance of the current Object.

optimizeUniversalStyleCompaction

java.lang.Object optimizeUniversalStyleCompaction(long memtableMemoryBudget)

Default values for some parameters in ColumnFamilyOptions are not optimized for heavy workloads and big datasets, which means you might observe write stalls under some conditions. As a starting point for tuning RocksDB options, use the following for universal style compaction.

Universal style compaction is focused on reducing Write Amplification Factor for big data sets, but increases Space Amplification.

Make sure to also call IncreaseParallelism(), which will provide the biggest performance gains.

Note: we might use more memory than memtable_memory_budget during high write rate period

Parameters:

memtableMemoryBudget - memory budget in bytes

Returns:

the instance of the current Object.

setComparator

java.lang.Object setComparator(BuiltinComparator builtinComparator)

Set BuiltinComparator to be used with RocksDB. Note: Comparator can be set once upon database creation. Default: BytewiseComparator.

Parameters:

builtinComparator - a BuiltinComparator type.

Returns:

the instance of the current Object.

setComparator

java.lang.Object setComparator(AbstractComparator<? extends AbstractSlice<?>> comparator)

Use the specified comparator for key ordering. Comparator should not be disposed before options instances using this comparator is disposed. If dispose() function is not called, then comparator object will be GC'd automatically. Comparator instance can be re-used in multiple options instances.

Parameters:

comparator - java instance.

Returns:

the instance of the current Object.

setMergeOperatorName

java.lang.Object setMergeOperatorName(java.lang.String name)

Set the merge operator to be used for merging two merge operands of the same key. The merge function is invoked during compaction and at lookup time, if multiple key/value pairs belonging to the same key are found in the database.

Parameters:

name - the name of the merge function, as defined by the MergeOperators factory (see utilities/MergeOperators.h) The merge function is specified by name and must be one of the standard merge operators provided by RocksDB. The available operators are "put", "uint64add", "stringappend" and "stringappendtest".

Returns:

the instance of the current Object.

setMergeOperator

java.lang.Object setMergeOperator(MergeOperator mergeOperator)

Set the merge operator to be used for merging two different key/value pairs that share the same key. The merge function is invoked during compaction and at lookup time, if multiple key/value pairs belonging to the same key are found in the database.

Parameters:

mergeOperator - MergeOperator instance.

Returns:

the instance of the current Object.

setMinWriteBufferNumberToMerge

java.lang.Object setMinWriteBufferNumberToMerge(int minWriteBufferNumberToMerge)

The minimum number of write buffers that will be merged together before writing to storage. If set to 1, then all write buffers are flushed to L0 as individual files and this increases read amplification because a get request has to check in all of these files. Also, an in-memory merge may result in writing lesser data to storage if there are duplicate records in each of these individual write buffers. Default: 1

Parameters:

minWriteBufferNumberToMerge - the minimum number of write buffers that will be merged together.

Returns:

the reference to the current option.

minWriteBufferNumberToMerge

int minWriteBufferNumberToMerge()

The minimum number of write buffers that will be merged together before writing to storage. If set to 1, then all write buffers are flushed to L0 as individual files and this increases read amplification because a get request has to check in all of these files. Also, an in-memory merge may result in writing lesser data to storage if there are duplicate records in each of these individual write buffers. Default: 1

Returns:

the minimum number of write buffers that will be merged together.

useFixedLengthPrefixExtractor

java.lang.Object useFixedLengthPrefixExtractor(int n)

This prefix-extractor uses the first n bytes of a key as its prefix. In some hash-based memtable representation such as HashLinkedList and HashSkipList, prefixes are used to partition the keys into several buckets. Prefix extractor is used to specify how to extract the prefix given a key.

Parameters:

n - use the first n bytes of a key as its prefix.

Returns:

the reference to the current option.

useCappedPrefixExtractor

java.lang.Object useCappedPrefixExtractor(int n)

Same as fixed length prefix extractor, except that when slice is shorter than the fixed length, it will use the full key.

Parameters:

n - use the first n bytes of a key as its prefix.

Returns:

the reference to the current option.

setCompressionType

java.lang.Object setCompressionType(CompressionType compressionType)

Compress blocks using the specified compression algorithm. This parameter can be changed dynamically. Default: SNAPPY_COMPRESSION, which gives lightweight but fast compression.

Parameters:

compressionType - Compression Type.

Returns:

the reference to the current option.

compressionType

CompressionType compressionType()

Compress blocks using the specified compression algorithm. This parameter can be changed dynamically. Default: SNAPPY_COMPRESSION, which gives lightweight but fast compression.

Returns:

Compression type.

setCompressionPerLevel

java.lang.Object setCompressionPerLevel(java.util.List<CompressionType> compressionLevels)

Different levels can have different compression policies. There are cases where most lower levels would like to use quick compression algorithms while the higher levels (which have more data) use compression algorithms that have better compression but could be slower. This array, if non-empty, should have an entry for each level of the database; these override the value specified in the previous field 'compression'.

NOTICE

If level_compaction_dynamic_level_bytes=true, compression_per_level[0] still determines L0, but other elements of the array are based on base level (the level L0 files are merged to), and may not match the level users see from info log for metadata.

If L0 files are merged to level - n, then, for i>0, compression_per_level[i] determines compaction type for level n+i-1.

Example

For example, if we have 5 levels, and we determine to merge L0 data to L4 (which means L1..L3 will be empty), then the new files go to L4 uses compression type compression_per_level[1].

If now L0 is merged to L2. Data goes to L2 will be compressed according to compression_per_level[1], L3 using compression_per_level[2]and L4 using compression_per_level[3]. Compaction for each level can change when data grows.

Default: empty

Parameters:

compressionLevels - list of CompressionType instances.

Returns:

the reference to the current option.

compressionPerLevel

java.util.List<CompressionType> compressionPerLevel()

Return the currently set CompressionType per instances.

See: setCompressionPerLevel(java.util.List)

Returns:

list of CompressionType instances.

setNumLevels

java.lang.Object setNumLevels(int numLevels)

Set the number of levels for this database If level-styled compaction is used, then this number determines the total number of levels.

Parameters:

numLevels - the number of levels.

Returns:

the reference to the current option.

numLevels

int numLevels()

If level-styled compaction is used, then this number determines the total number of levels.

Returns:

the number of levels.

setLevelZeroFileNumCompactionTrigger

java.lang.Object setLevelZeroFileNumCompactionTrigger(int numFiles)

Number of files to trigger level-0 compaction. A value < 0 means that level-0 compaction will not be triggered by number of files at all. Default: 4

Parameters:

numFiles - the number of files in level-0 to trigger compaction.

Returns:

the reference to the current option.

levelZeroFileNumCompactionTrigger

int levelZeroFileNumCompactionTrigger()

The number of files in level 0 to trigger compaction from level-0 to level-1. A value < 0 means that level-0 compaction will not be triggered by number of files at all. Default: 4

Returns:

the number of files in level 0 to trigger compaction.

setLevelZeroSlowdownWritesTrigger

java.lang.Object setLevelZeroSlowdownWritesTrigger(int numFiles)

Soft limit on number of level-0 files. We start slowing down writes at this point. A value < 0 means that no writing slow down will be triggered by number of files in level-0.

Parameters:

numFiles - soft limit on number of level-0 files.

Returns:

the reference to the current option.

levelZeroSlowdownWritesTrigger

int levelZeroSlowdownWritesTrigger()

Soft limit on the number of level-0 files. We start slowing down writes at this point. A value < 0 means that no writing slow down will be triggered by number of files in level-0.

Returns:

the soft limit on the number of level-0 files.

setLevelZeroStopWritesTrigger

java.lang.Object setLevelZeroStopWritesTrigger(int numFiles)

Maximum number of level-0 files. We stop writes at this point.

Parameters:

numFiles - the hard limit of the number of level-0 files.

Returns:

the reference to the current option.

levelZeroStopWritesTrigger

int levelZeroStopWritesTrigger()

Maximum number of level-0 files. We stop writes at this point.

Returns:

the hard limit of the number of level-0 file.

setMaxMemCompactionLevel

@Deprecated
java.lang.Object setMaxMemCompactionLevel(int maxMemCompactionLevel)

Deprecated.

This does nothing anymore. Deprecated.

Parameters:

maxMemCompactionLevel - Unused.

Returns:

the reference to the current option.

maxMemCompactionLevel

@Deprecated
int maxMemCompactionLevel()

Deprecated.

This does nothing anymore. Deprecated.

Returns:

Always returns 0.

setLevelCompactionDynamicLevelBytes

java.lang.Object setLevelCompactionDynamicLevelBytes(boolean enableLevelCompactionDynamicLevelBytes)

If true, RocksDB will pick target size of each level dynamically. We will pick a base level b >= 1. L0 will be directly merged into level b, instead of always into level 1. Level 1 to b-1 need to be empty. We try to pick b and its target size so that

1. target size is in the range of (max_bytes_for_level_base / max_bytes_for_level_multiplier, max_bytes_for_level_base]
2. target size of the last level (level num_levels-1) equals to extra size of the level.

At the same time max_bytes_for_level_multiplier and max_bytes_for_level_multiplier_additional are still satisfied.

With this option on, from an empty DB, we make last level the base level, which means merging L0 data into the last level, until it exceeds max_bytes_for_level_base. And then we make the second last level to be base level, to start to merge L0 data to second last level, with its target size to be 1/max_bytes_for_level_multiplier of the last levels extra size. After the data accumulates more so that we need to move the base level to the third last one, and so on.

Example

For example, assume max_bytes_for_level_multiplier=10, num_levels=6, and max_bytes_for_level_base=10MB.

Target sizes of level 1 to 5 starts with:

[- - - - 10MB]

with base level is level. Target sizes of level 1 to 4 are not applicable because they will not be used. Until the size of Level 5 grows to more than 10MB, say 11MB, we make base target to level 4 and now the targets looks like:

[- - - 1.1MB 11MB]

While data are accumulated, size targets are tuned based on actual data of level 5. When level 5 has 50MB of data, the target is like:

[- - - 5MB 50MB]

Until level 5's actual size is more than 100MB, say 101MB. Now if we keep level 4 to be the base level, its target size needs to be 10.1MB, which doesn't satisfy the target size range. So now we make level 3 the target size and the target sizes of the levels look like:

[- - 1.01MB 10.1MB 101MB]

In the same way, while level 5 further grows, all levels' targets grow, like

[- - 5MB 50MB 500MB]

Until level 5 exceeds 1000MB and becomes 1001MB, we make level 2 the base level and make levels' target sizes like this:

[- 1.001MB 10.01MB 100.1MB 1001MB]

and go on...

By doing it, we give max_bytes_for_level_multiplier a priority against max_bytes_for_level_base, for a more predictable LSM tree shape. It is useful to limit worse case space amplification.

max_bytes_for_level_multiplier_additional is ignored with this flag on.

Turning this feature on or off for an existing DB can cause unexpected LSM tree structure so it's not recommended.

Caution: this option is experimental

Default: false

Parameters:

enableLevelCompactionDynamicLevelBytes - boolean value indicating if LevelCompactionDynamicLevelBytes shall be enabled.

Returns:

the reference to the current option.

levelCompactionDynamicLevelBytes

boolean levelCompactionDynamicLevelBytes()

Return if LevelCompactionDynamicLevelBytes is enabled.

For further information see setLevelCompactionDynamicLevelBytes(boolean)

Returns:

boolean value indicating if levelCompactionDynamicLevelBytes is enabled.

setMaxBytesForLevelMultiplier

java.lang.Object setMaxBytesForLevelMultiplier(double multiplier)

The ratio between the total size of level-(L+1) files and the total size of level-L files for all L. DEFAULT: 10

Parameters:

multiplier - the ratio between the total size of level-(L+1) files and the total size of level-L files for all L.

Returns:

the reference to the current option.

maxBytesForLevelMultiplier

double maxBytesForLevelMultiplier()

The ratio between the total size of level-(L+1) files and the total size of level-L files for all L. DEFAULT: 10

Returns:

the ratio between the total size of level-(L+1) files and the total size of level-L files for all L.

setMaxCompactionBytes

java.lang.Object setMaxCompactionBytes(long maxCompactionBytes)

Maximum size of each compaction (not guarantee)

Parameters:

maxCompactionBytes - the compaction size limit

Returns:

the reference to the current option.

maxCompactionBytes

long maxCompactionBytes()

Control maximum size of each compaction (not guaranteed)

Returns:

compaction size threshold

setSoftRateLimit

java.lang.Object setSoftRateLimit(double softRateLimit)

Puts are delayed 0-1 ms when any level has a compaction score that exceeds soft_rate_limit. This is ignored when == 0.0. CONSTRAINT: soft_rate_limit ≤ hard_rate_limit. If this constraint does not hold, RocksDB will set soft_rate_limit = hard_rate_limit Default: 0 (disabled)

Parameters:

softRateLimit - the soft-rate-limit of a compaction score for put delay.

Returns:

the reference to the current option.

softRateLimit

double softRateLimit()

Puts are delayed 0-1 ms when any level has a compaction score that exceeds soft_rate_limit. This is ignored when == 0.0. CONSTRAINT: soft_rate_limit ≤ hard_rate_limit. If this constraint does not hold, RocksDB will set soft_rate_limit = hard_rate_limit Default: 0 (disabled)

Returns:

soft-rate-limit for put delay.

setHardRateLimit

java.lang.Object setHardRateLimit(double hardRateLimit)

Puts are delayed 1ms at a time when any level has a compaction score that exceeds hard_rate_limit. This is ignored when ≤ 1.0. Default: 0 (disabled)

Parameters:

hardRateLimit - the hard-rate-limit of a compaction score for put delay.

Returns:

the reference to the current option.

hardRateLimit

double hardRateLimit()

Puts are delayed 1ms at a time when any level has a compaction score that exceeds hard_rate_limit. This is ignored when ≤ 1.0. Default: 0 (disabled)

Returns:

the hard-rate-limit of a compaction score for put delay.

setRateLimitDelayMaxMilliseconds

java.lang.Object setRateLimitDelayMaxMilliseconds(int rateLimitDelayMaxMilliseconds)

The maximum time interval a put will be stalled when hard_rate_limit is enforced. If 0, then there is no limit. Default: 1000

Parameters:

rateLimitDelayMaxMilliseconds - the maximum time interval a put will be stalled.

Returns:

the reference to the current option.

rateLimitDelayMaxMilliseconds

int rateLimitDelayMaxMilliseconds()

The maximum time interval a put will be stalled when hard_rate_limit is enforced. If 0, then there is no limit. Default: 1000

Returns:

the maximum time interval a put will be stalled when hard_rate_limit is enforced.

setPurgeRedundantKvsWhileFlush

java.lang.Object setPurgeRedundantKvsWhileFlush(boolean purgeRedundantKvsWhileFlush)

Purge duplicate/deleted keys when a memtable is flushed to storage. Default: true

Parameters:

purgeRedundantKvsWhileFlush - true if purging keys is disabled.

Returns:

the reference to the current option.

purgeRedundantKvsWhileFlush

boolean purgeRedundantKvsWhileFlush()

Purge duplicate/deleted keys when a memtable is flushed to storage. Default: true

Returns:

true if purging keys is disabled.

setCompactionStyle

java.lang.Object setCompactionStyle(CompactionStyle compactionStyle)

Set compaction style for DB. Default: LEVEL.

Parameters:

compactionStyle - Compaction style.

Returns:

the reference to the current option.

compactionStyle

CompactionStyle compactionStyle()

Compaction style for DB.

Returns:

Compaction style.

setMaxTableFilesSizeFIFO

java.lang.Object setMaxTableFilesSizeFIFO(long maxTableFilesSize)

FIFO compaction option. The oldest table file will be deleted once the sum of table files reaches this size. The default value is 1GB (1 * 1024 * 1024 * 1024).

Parameters:

maxTableFilesSize - the size limit of the total sum of table files.

Returns:

the instance of the current Object.

maxTableFilesSizeFIFO

long maxTableFilesSizeFIFO()

FIFO compaction option. The oldest table file will be deleted once the sum of table files reaches this size. The default value is 1GB (1 * 1024 * 1024 * 1024).

Returns:

the size limit of the total sum of table files.

setMemTableConfig

java.lang.Object setMemTableConfig(MemTableConfig config)

Set the config for mem-table.

Parameters:

config - the mem-table config.

Returns:

the instance of the current Object.

Throws:

java.lang.IllegalArgumentException - thrown on 32-Bit platforms while overflowing the underlying platform specific value.

memTableFactoryName

java.lang.String memTableFactoryName()

Returns the name of the current mem table representation. Memtable format can be set using setTableFormatConfig.

Returns:

the name of the currently-used memtable factory.

See Also:

setTableFormatConfig(org.rocksdb.TableFormatConfig)

setTableFormatConfig

java.lang.Object setTableFormatConfig(TableFormatConfig config)

Set the config for table format.

Parameters:

config - the table format config.

Returns:

the reference of the current Options.

tableFactoryName

java.lang.String tableFactoryName()

Returns:

the name of the currently used table factory.

setInplaceUpdateSupport

java.lang.Object setInplaceUpdateSupport(boolean inplaceUpdateSupport)

Allows thread-safe inplace updates. If inplace_callback function is not set, Put(key, new_value) will update inplace the existing_value iff * key exists in current memtable * new sizeof(new_value) ≤ sizeof(existing_value) * existing_value for that key is a put i.e. kTypeValue If inplace_callback function is set, check doc for inplace_callback. Default: false.

Parameters:

inplaceUpdateSupport - true if thread-safe inplace updates are allowed.

Returns:

the reference to the current option.

inplaceUpdateSupport

boolean inplaceUpdateSupport()

Allows thread-safe inplace updates. If inplace_callback function is not set, Put(key, new_value) will update inplace the existing_value iff * key exists in current memtable * new sizeof(new_value) ≤ sizeof(existing_value) * existing_value for that key is a put i.e. kTypeValue If inplace_callback function is set, check doc for inplace_callback. Default: false.

Returns:

true if thread-safe inplace updates are allowed.

setBloomLocality

java.lang.Object setBloomLocality(int bloomLocality)

Control locality of bloom filter probes to improve cache miss rate. This option only applies to memtable prefix bloom and plaintable prefix bloom. It essentially limits the max number of cache lines each bloom filter check can touch. This optimization is turned off when set to 0. The number should never be greater than number of probes. This option can boost performance for in-memory workload but should use with care since it can cause higher false positive rate. Default: 0

Parameters:

bloomLocality - the level of locality of bloom-filter probes.

Returns:

the reference to the current option.

bloomLocality

int bloomLocality()

Control locality of bloom filter probes to improve cache miss rate. This option only applies to memtable prefix bloom and plaintable prefix bloom. It essentially limits the max number of cache lines each bloom filter check can touch. This optimization is turned off when set to 0. The number should never be greater than number of probes. This option can boost performance for in-memory workload but should use with care since it can cause higher false positive rate. Default: 0

Returns:

the level of locality of bloom-filter probes.

See Also:

setBloomLocality(int)

setMinPartialMergeOperands

java.lang.Object setMinPartialMergeOperands(int minPartialMergeOperands)

The number of partial merge operands to accumulate before partial merge will be performed. Partial merge will not be called if the list of values to merge is less than min_partial_merge_operands. If min_partial_merge_operands < 2, then it will be treated as 2. Default: 2

Parameters:

minPartialMergeOperands - min partial merge operands

Returns:

the reference to the current option.

minPartialMergeOperands

int minPartialMergeOperands()

The number of partial merge operands to accumulate before partial merge will be performed. Partial merge will not be called if the list of values to merge is less than min_partial_merge_operands. If min_partial_merge_operands < 2, then it will be treated as 2. Default: 2

Returns:

min partial merge operands

setOptimizeFiltersForHits

java.lang.Object setOptimizeFiltersForHits(boolean optimizeFiltersForHits)

This flag specifies that the implementation should optimize the filters mainly for cases where keys are found rather than also optimize for keys missed. This would be used in cases where the application knows that there are very few misses or the performance in the case of misses is not important.

For now, this flag allows us to not store filters for the last level i.e the largest level which contains data of the LSM store. For keys which are hits, the filters in this level are not useful because we will search for the data anyway.

NOTE: the filters in other levels are still useful even for key hit because they tell us whether to look in that level or go to the higher level.

Default: false

Parameters:

optimizeFiltersForHits - boolean value indicating if this flag is set.

Returns:

the reference to the current option.

optimizeFiltersForHits

boolean optimizeFiltersForHits()

Returns the current state of the optimize_filters_for_hits setting.

Returns:

boolean value indicating if the flag optimize_filters_for_hits was set.