The highest tagged major version is
README
¶
Size of table is 122,173,606 bytes for all benchmarks.
BenchmarkRead
$ go test -bench ^BenchmarkRead$ -run ^$ -count 3
goos: linux
goarch: amd64
pkg: github.com/dgraph-io/badger/table
BenchmarkRead-16 10 153281932 ns/op
BenchmarkRead-16 10 153454443 ns/op
BenchmarkRead-16 10 155349696 ns/op
PASS
ok github.com/dgraph-io/badger/table 23.549s
Size of table is 122,173,606 bytes, which is ~117MB.
The rate is ~750MB/s using LoadToRAM (when table is in RAM).
To read a 64MB table, this would take ~0.0853s, which is negligible.
BenchmarkReadAndBuild
$ go test -bench BenchmarkReadAndBuild -run ^$ -count 3
goos: linux
goarch: amd64
pkg: github.com/dgraph-io/badger/table
BenchmarkReadAndBuild-16 2 945041628 ns/op
BenchmarkReadAndBuild-16 2 947120893 ns/op
BenchmarkReadAndBuild-16 2 954909506 ns/op
PASS
ok github.com/dgraph-io/badger/table 26.856s
The rate is ~122MB/s. To build a 64MB table, this would take ~0.52s. Note that this does NOT include the flushing of the table to disk. All we are doing above is reading one table (which is in RAM) and write one table in memory.
The table building takes 0.52-0.0853s ~ 0.4347s.
BenchmarkReadMerged
Below, we merge 5 tables. The total size remains unchanged at ~122M.
$ go test -bench ReadMerged -run ^$ -count 3
BenchmarkReadMerged-16 2 954475788 ns/op
BenchmarkReadMerged-16 2 955252462 ns/op
BenchmarkReadMerged-16 2 956857353 ns/op
PASS
ok github.com/dgraph-io/badger/table 33.327s
The rate is ~122MB/s. To read a 64MB table using merge iterator, this would take ~0.52s.
BenchmarkRandomRead
go test -bench BenchmarkRandomRead$ -run ^$ -count 3
goos: linux
goarch: amd64
pkg: github.com/dgraph-io/badger/table
BenchmarkRandomRead-16 300000 3596 ns/op
BenchmarkRandomRead-16 300000 3621 ns/op
BenchmarkRandomRead-16 300000 3596 ns/op
PASS
ok github.com/dgraph-io/badger/table 44.727s
For random read benchmarking, we are randomly reading a key and verifying its value.
Documentation
¶
Index ¶
- func IDToFilename(id uint64) string
- func NewFilename(id uint64, dir string) string
- func NewMergeIterator(iters []y.Iterator, reverse bool) y.Iterator
- func ParseFileID(name string) (uint64, bool)
- type Builder
- type ConcatIterator
- type Iterator
- type MergeIterator
- type Table
- func (t *Table) Biggest() []byte
- func (t *Table) Close() error
- func (t *Table) DecrRef() error
- func (t *Table) DoesNotHave(key []byte) bool
- func (t *Table) Filename() string
- func (t *Table) ID() uint64
- func (t *Table) IncrRef()
- func (t *Table) NewIterator(reversed bool) *Iterator
- func (t *Table) Size() int64
- func (t *Table) Smallest() []byte
- type TableInterface
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func IDToFilename ¶
IDToFilename does the inverse of ParseFileID
func NewFilename ¶
NewFilename should be named TableFilepath -- it combines the dir with the ID to make a table filepath.
func NewMergeIterator ¶ added in v1.6.1
NewMergeIterator creates a merge iterator.
func ParseFileID ¶
ParseFileID reads the file id out of a filename.
Types ¶
type Builder ¶
type Builder struct {
// contains filtered or unexported fields
}
Builder is used in building a table.
func (*Builder) Add ¶
func (b *Builder) Add(key []byte, value y.ValueStruct)
Add adds a key-value pair to the block. If doNotRestart is true, we will not restart even if b.counter >= restartInterval.
func (*Builder) ReachedCapacity ¶
ReachedCapacity returns true if we... roughly (?) reached capacity?
type ConcatIterator ¶
type ConcatIterator struct {
// contains filtered or unexported fields
}
ConcatIterator concatenates the sequences defined by several iterators. (It only works with TableIterators, probably just because it's faster to not be so generic.)
func NewConcatIterator ¶
func NewConcatIterator(tbls []*Table, reversed bool) *ConcatIterator
NewConcatIterator creates a new concatenated iterator
func (*ConcatIterator) Seek ¶
func (s *ConcatIterator) Seek(key []byte)
Seek brings us to element >= key if reversed is false. Otherwise, <= key.
func (*ConcatIterator) Value ¶
func (s *ConcatIterator) Value() y.ValueStruct
Value implements y.Interface
type Iterator ¶
type Iterator struct {
// contains filtered or unexported fields
}
Iterator is an iterator for a Table.
func (*Iterator) Value ¶
func (itr *Iterator) Value() (ret y.ValueStruct)
Value follows the y.Iterator interface
type MergeIterator ¶ added in v1.6.1
type MergeIterator struct {
// contains filtered or unexported fields
}
MergeIterator merges multiple iterators. NOTE: MergeIterator owns the array of iterators and is responsible for closing them.
func (*MergeIterator) Close ¶ added in v1.6.1
func (mi *MergeIterator) Close() error
Close implements y.Iterator.
func (*MergeIterator) Key ¶ added in v1.6.1
func (mi *MergeIterator) Key() []byte
Key returns the key associated with the current iterator.
func (*MergeIterator) Next ¶ added in v1.6.1
func (mi *MergeIterator) Next()
Next returns the next element. If it is the same as the current key, ignore it.
func (*MergeIterator) Rewind ¶ added in v1.6.1
func (mi *MergeIterator) Rewind()
Rewind seeks to first element (or last element for reverse iterator).
func (*MergeIterator) Seek ¶ added in v1.6.1
func (mi *MergeIterator) Seek(key []byte)
Seek brings us to element with key >= given key.
func (*MergeIterator) Valid ¶ added in v1.6.1
func (mi *MergeIterator) Valid() bool
Valid returns whether the MergeIterator is at a valid element.
func (*MergeIterator) Value ¶ added in v1.6.1
func (mi *MergeIterator) Value() y.ValueStruct
Value returns the value associated with the iterator.
type Table ¶
Table represents a loaded table file with the info we have about it
func OpenTable ¶
OpenTable assumes file has only one table and opens it. Takes ownership of fd upon function entry. Returns a table with one reference count on it (decrementing which may delete the file! -- consider t.Close() instead). The fd has to writeable because we call Truncate on it before deleting.
func (*Table) DoesNotHave ¶
DoesNotHave returns true if (but not "only if") the table does not have the key. It does a bloom filter lookup.
func (*Table) IncrRef ¶
func (t *Table) IncrRef()
IncrRef increments the refcount (having to do with whether the file should be deleted)
func (*Table) NewIterator ¶
NewIterator returns a new iterator of the Table
Source Files