Package org.rocksdb

Class TransactionDBOptions

  • All Implemented Interfaces:
    java.lang.AutoCloseable
    public class TransactionDBOptions
extends RocksObject

    • Constructor Detail

      • TransactionDBOptions

        public TransactionDBOptions()

    • Method Detail

      • getMaxNumLocks

        public long getMaxNumLocks()
        Specifies the maximum number of keys that can be locked at the same time per column family. If the number of locked keys is greater than getMaxNumLocks(), transaction writes (or GetForUpdate) will return an error.
        Returns:
        The maximum number of keys that can be locked

      • setMaxNumLocks

        public TransactionDBOptions setMaxNumLocks​(long maxNumLocks)
        Specifies the maximum number of keys that can be locked at the same time per column family. If the number of locked keys is greater than getMaxNumLocks(), transaction writes (or GetForUpdate) will return an error.
        Parameters:
        maxNumLocks - The maximum number of keys that can be locked; If this value is not positive, no limit will be enforced.
        Returns:
        this TransactionDBOptions instance

      • getNumStripes

        public long getNumStripes()
        The number of sub-tables per lock table (per column family)
        Returns:
        The number of sub-tables

      • setNumStripes

        public TransactionDBOptions setNumStripes​(long numStripes)
        Increasing this value will increase the concurrency by dividing the lock table (per column family) into more sub-tables, each with their own separate mutex. Default: 16
        Parameters:
        numStripes - The number of sub-tables
        Returns:
        this TransactionDBOptions instance

      • getTransactionLockTimeout

        public long getTransactionLockTimeout()
        The default wait timeout in milliseconds when a transaction attempts to lock a key if not specified by TransactionOptions.setLockTimeout(long) If 0, no waiting is done if a lock cannot instantly be acquired. If negative, there is no timeout.
        Returns:
        the default wait timeout in milliseconds

      • setTransactionLockTimeout

        public TransactionDBOptions setTransactionLockTimeout​(long transactionLockTimeout)
        If positive, specifies the default wait timeout in milliseconds when a transaction attempts to lock a key if not specified by TransactionOptions.setLockTimeout(long) If 0, no waiting is done if a lock cannot instantly be acquired. If negative, there is no timeout. Not using a timeout is not recommended as it can lead to deadlocks. Currently, there is no deadlock-detection to recover from a deadlock. Default: 1000
        Parameters:
        transactionLockTimeout - the default wait timeout in milliseconds
        Returns:
        this TransactionDBOptions instance

      • setDefaultLockTimeout

        public TransactionDBOptions setDefaultLockTimeout​(long defaultLockTimeout)
        If positive, specifies the wait timeout in milliseconds when writing a key OUTSIDE of a transaction (ie by calling RocksDB.put(byte[], byte[]), RocksDB.merge(byte[], byte[]), RocksDB.delete(byte[]) or RocksDB.write(org.rocksdb.WriteOptions, org.rocksdb.WriteBatch) directly). If 0, no waiting is done if a lock cannot instantly be acquired. If negative, there is no timeout and will block indefinitely when acquiring a lock. Not using a timeout can lead to deadlocks. Currently, there is no deadlock-detection to recover from a deadlock. While DB writes cannot deadlock with other DB writes, they can deadlock with a transaction. A negative timeout should only be used if all transactions have a small expiration set. Default: 1000
        Parameters:
        defaultLockTimeout - the timeout in milliseconds when writing a key OUTSIDE of a transaction
        Returns:
        this TransactionDBOptions instance

      • getWritePolicy

        public TxnDBWritePolicy getWritePolicy()
        The policy for when to write the data into the DB. The default policy is to write only the committed data TxnDBWritePolicy.WRITE_COMMITTED. The data could be written before the commit phase. The DB then needs to provide the mechanisms to tell apart committed from uncommitted data.
        Returns:
        The write policy.

      • setWritePolicy

        public TransactionDBOptions setWritePolicy​(TxnDBWritePolicy writePolicy)
        The policy for when to write the data into the DB. The default policy is to write only the committed data TxnDBWritePolicy.WRITE_COMMITTED. The data could be written before the commit phase. The DB then needs to provide the mechanisms to tell apart committed from uncommitted data.
        Parameters:
        writePolicy - The write policy.
        Returns:
        this TransactionDBOptions instance