@ -191,13 +191,18 @@ struct ColumnFamilyOptions {
// the next time the database is opened.
//
// Default: 4MB
//
// Dynamically changeable through SetOptions() API
size_t write_buffer_size ;
// The maximum number of write buffers that are built up in memory.
// The default and the minimum number is 2, so that when 1 write buffer
// is being flushed to storage, new writes can continue to the other
// write buffer.
//
// Default: 2
//
// Dynamically changeable through SetOptions() API
int max_write_buffer_number ;
// The minimum number of write buffers that will be merged together
@ -260,14 +265,20 @@ struct ColumnFamilyOptions {
// level-0 compaction will not be triggered by number of files at all.
//
// Default: 4
//
// Dynamically changeable through SetOptions() API
int level0_file_num_compaction_trigger ;
// 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.
//
// Dynamically changeable through SetOptions() API
int level0_slowdown_writes_trigger ;
// Maximum number of level-0 files. We stop writes at this point.
//
// Dynamically changeable through SetOptions() API
int level0_stop_writes_trigger ;
// Maximum level to which a new compacted memtable is pushed if it
@ -276,6 +287,8 @@ struct ColumnFamilyOptions {
// expensive manifest file operations. We do not push all the way to
// the largest level since that can generate a lot of wasted disk
// space if the same key space is being repeatedly overwritten.
//
// Dynamically changeable through SetOptions() API
int max_mem_compaction_level ;
// Target file size for compaction.
@ -286,11 +299,15 @@ struct ColumnFamilyOptions {
// target_file_size_multiplier is 10, then each file on level-1 will
// be 2MB, and each file on level 2 will be 20MB,
// and each file on level-3 will be 200MB.
// by default target_file_size_base is 2MB.
//
// Default: 2MB.
//
// Dynamically changeable through SetOptions() API
uint64_t target_file_size_base ;
// by default target_file_size_multiplier is 1, which means
// B y default target_file_size_multiplier is 1, which means
// by default files in different levels will have similar size.
//
// Dynamically changeable through SetOptions() API
int target_file_size_multiplier ;
// Control maximum total data size for a level.
@ -301,22 +318,31 @@ struct ColumnFamilyOptions {
// max_bytes_for_level_multiplier is 10, total data size for level-1
// will be 20MB, total file size for level-2 will be 200MB,
// and total file size for level-3 will be 2GB.
// by default 'max_bytes_for_level_base' is 10MB.
//
// Default: 10MB.
//
// Dynamically changeable through SetOptions() API
uint64_t max_bytes_for_level_base ;
// by default 'max_bytes_for_level_base' is 10.
// Default: 10.
//
// Dynamically changeable through SetOptions() API
int max_bytes_for_level_multiplier ;
// Different max-size multipliers for different levels.
// These are multiplied by max_bytes_for_level_multiplier to arrive
// at the max-size of each level.
//
// Default: 1
//
// Dynamically changeable through SetOptions() API
std : : vector < int > max_bytes_for_level_multiplier_additional ;
// Maximum number of bytes in all compacted files. We avoid expanding
// the lower level file set of a compaction if it would make the
// total compaction cover more than
// (expanded_compaction_factor * targetFileSizeLevel()) many bytes.
//
// Dynamically changeable through SetOptions() API
int expanded_compaction_factor ;
// Maximum number of bytes in all source files to be compacted in a
@ -326,22 +352,32 @@ struct ColumnFamilyOptions {
// (source_compaction_factor * targetFileSizeLevel()) many bytes.
// Default:1, i.e. pick maxfilesize amount of data as the source of
// a compaction.
//
// Dynamically changeable through SetOptions() API
int source_compaction_factor ;
// Control maximum bytes of overlaps in grandparent (i.e., level+2) before we
// stop building a single file in a level->level+1 compaction.
//
// Dynamically changeable through SetOptions() API
int max_grandparent_overlap_factor ;
// 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)
//
// Dynamically changeable through SetOptions() API
double soft_rate_limit ;
// 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)
//
// Dynamically changeable through SetOptions() API
double hard_rate_limit ;
// DEPRECATED -- this options is no longer used
@ -360,10 +396,14 @@ struct ColumnFamilyOptions {
// conforms to the restrictions.
//
// Default: 0
//
// Dynamically changeable through SetOptions() API
size_t arena_block_size ;
// Disable automatic compactions. Manual compactions can still
// be issued on this column family
//
// Dynamically changeable through SetOptions() API
bool disable_auto_compactions ;
// Purge duplicate/deleted keys when a memtable is flushed to storage.
@ -388,14 +428,20 @@ struct ColumnFamilyOptions {
// If KeyMayExist returns false, i.e. the key definitely does not exist, then
// the delete is a noop. KeyMayExist only incurs in-memory look up.
// This optimization avoids writing the delete to storage when appropriate.
//
// Default: false
//
// Dynamically changeable through SetOptions() API
bool filter_deletes ;
// An iteration->Next() sequentially skips over keys with the same
// user-key unless this option is set. This number specifies the number
// of keys (with the same userkey) that will be sequentially
// skipped before a reseek is issued.
//
// Default: 8
//
// Dynamically changeable through SetOptions() API
uint64_t max_sequential_skip_in_iterations ;
// This is a factory that provides MemTableRep objects.
@ -444,6 +490,8 @@ struct ColumnFamilyOptions {
// Number of locks used for inplace update
// Default: 10000, if inplace_update_support = true, else 0.
//
// Dynamically changeable through SetOptions() API
size_t inplace_update_num_locks ;
// existing_value - pointer to previous value (from both memtable and sst).
@ -490,9 +538,13 @@ struct ColumnFamilyOptions {
// if prefix_extractor is set and bloom_bits is not 0, create prefix bloom
// for memtable
//
// Dynamically changeable through SetOptions() API
uint32_t memtable_prefix_bloom_bits ;
// number of hash probes per key
//
// Dynamically changeable through SetOptions() API
uint32_t memtable_prefix_bloom_probes ;
// Page size for huge page TLB for bloom in memtable. If <=0, not allocate
@ -500,7 +552,8 @@ struct ColumnFamilyOptions {
// Need to reserve huge pages for it to be allocated. For example:
// sysctl -w vm.nr_hugepages=20
// See linux doc Documentation/vm/hugetlbpage.txt
//
// Dynamically changeable through SetOptions() API
size_t memtable_prefix_bloom_huge_page_tlb_size ;
// Control locality of bloom filter probes to improve cache miss rate.
@ -520,6 +573,8 @@ struct ColumnFamilyOptions {
// operations in the memtable.
//
// Default: 0 (disabled)
//
// Dynamically changeable through SetOptions() API
size_t max_successive_merges ;
// The number of partial merge operands to accumulate before partial