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// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
// All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package leveldb
const (
kNumLevels = 7
// Level-0 compaction is started when we hit this many files.
kL0_CompactionTrigger float64 = 4
// Soft limit on number of level-0 files. We slow down writes at this point.
kL0_SlowdownWritesTrigger = 8
// Maximum number of level-0 files. We stop writes at this point.
kL0_StopWritesTrigger = 12
// Maximum level to which a new compacted memdb is pushed if it
// does not create overlap. We try to push to level 2 to avoid the
// relatively expensive level 0=>1 compactions and to avoid some
// 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.
kMaxMemCompactLevel = 2
// Maximum size of a table.
kMaxTableSize = 2 * 1048576
// Maximum bytes of overlaps in grandparent (i.e., level+2) before we
// stop building a single file in a level->level+1 compaction.
kMaxGrandParentOverlapBytes = 10 * kMaxTableSize
// 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 this many bytes.
kExpCompactionMaxBytes = 25 * kMaxTableSize
)
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