dimgigov
e1bae0c7a0
- Add docs/ folder with English (en/) and Bulgarian (bg/) documentation - Create index.md with language switching and links - English docs: installation, quickstart, architecture, baraql, storage, schema, lsm, btree, vector, graph, fts, columnar, transactions, distributed, protocol, udf, api-binary, api-http, api-websocket - Bulgarian docs: installation, quickstart, architecture, baraql, schema, lsm, btree, vector, graph, fts, transactions, distributed - Update README license to BSD 3-Clause - Add LICENSE file with BSD 3-Clause text
78 lines
1.5 KiB
Markdown
78 lines
1.5 KiB
Markdown
# Storage Engines
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BaraDB provides multiple storage engines optimized for different access patterns.
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## LSM-Tree (Key-Value)
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The primary storage engine with write-optimized append-only log structure.
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### Usage
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```nim
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import barabadb/storage/lsm
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var db = newLSMTree("./data")
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db.put("key1", cast[seq[byte]]("value1"))
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let (found, value) = db.get("key1")
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db.close()
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```
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### Components
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- **MemTable**: In-memory sorted buffer
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- **WAL**: Write-ahead log for durability
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- **SSTable**: Sorted string tables on disk
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- **Bloom Filter**: Probabilistic set membership
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- **Compaction**: Size-tiered strategy with level management
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- **Page Cache**: LRU cache with hit rate tracking
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## B-Tree Index
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Ordered index for range scans and point lookups.
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### Usage
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```nim
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import barabadb/storage/btree
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var btree = newBTreeIndex[string, string]()
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btree.insert("key1", "value1")
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let values = btree.get("key1")
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let range = btree.scan("key_a", "key_z")
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```
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## Write-Ahead Log (WAL)
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Ensures durability of write operations.
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```nim
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import barabadb/storage/wal
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var wal = newWAL("./wal")
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wal.append("txn1", "SET key1 value1")
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wal.flush()
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```
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## Bloom Filter
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Probabilistic data structure for fast negative lookups.
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```nim
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import barabadb/storage/bloom
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var filter = newBloomFilter(10000, 0.01)
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filter.add("key1")
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if filter.mightContain("key1"):
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echo "possibly exists"
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```
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## Memory-mapped I/O
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Efficient file access using mmap.
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```nim
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import barabadb/storage/mmap
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var mapped = mmapFile("./data/file.dat")
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let data = mapped.read(0, 100)
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``` |