com.couchbase.lite.internal.database.sqlite

Class SQLiteGlobal

java.lang.Object

com.couchbase.lite.internal.database.sqlite.SQLiteGlobal

public final class SQLiteGlobal
extends java.lang.Object

Provides access to SQLite functions that affect all database connection, such as memory management. The native code associated with SQLiteGlobal is also sets global configuration options using sqlite3_config() then calls sqlite3_initialize() to ensure that the SQLite library is properly initialized exactly once before any other framework or application code has a chance to run.

Method Summary

Modifier and Type	Method and Description
static java.lang.String	getDefaultJournalMode() The default journal mode to use use when Write-Ahead Logging is not active.
static int	getDefaultPageSize() Gets the default page size to use when creating a database.
static java.lang.String	getDefaultSyncMode() Gets the default database synchronization mode when WAL is not in use.
static int	getJournalSizeLimit() Gets the journal size limit in bytes.
static int	getWALAutoCheckpoint() Gets the WAL auto-checkpoint integer in database pages.
static int	getWALConnectionPoolSize() Gets the connection pool size when in WAL mode.
static java.lang.String	getWALSyncMode() Gets the database synchronization mode when in WAL mode.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getDefaultPageSize

public static int getDefaultPageSize()

Gets the default page size to use when creating a database.

getDefaultJournalMode

public static java.lang.String getDefaultJournalMode()

The default journal mode to use use when Write-Ahead Logging is not active. Choices are: OFF, DELETE, TRUNCATE, PERSIST and MEMORY. PERSIST may improve performance by reducing how often journal blocks are reallocated (compared to truncation) resulting in better data block locality and less churn of the storage media. -->

getJournalSizeLimit

public static int getJournalSizeLimit()

Gets the journal size limit in bytes. Maximum size of the persistent journal file in bytes. If the journal file grows to be larger than this amount then SQLite will truncate it after committing the transaction.

getDefaultSyncMode

public static java.lang.String getDefaultSyncMode()

Gets the default database synchronization mode when WAL is not in use. The database synchronization mode when using the default journal mode. FULL is safest and preserves durability at the cost of extra fsyncs. NORMAL also preserves durability in non-WAL modes and uses checksums to ensure integrity although there is a small chance that an error might go unnoticed. Choices are: FULL, NORMAL, OFF.

getWALSyncMode

public static java.lang.String getWALSyncMode()

Gets the database synchronization mode when in WAL mode. The database synchronization mode when using Write-Ahead Logging. FULL is safest and preserves durability at the cost of extra fsyncs. NORMAL sacrifices durability in WAL mode because syncs are only performed before and after checkpoint operations. If checkpoints are infrequent and power loss occurs, then committed transactions could be lost and applications might break. Choices are: FULL, NORMAL, OFF.

getWALAutoCheckpoint

public static int getWALAutoCheckpoint()

Gets the WAL auto-checkpoint integer in database pages. The Write-Ahead Log auto-checkpoint interval in database pages (typically 1 to 4KB). The log is checkpointed automatically whenever it exceeds this many pages. When a database is reopened, its journal mode is set back to the default journal mode, which may cause a checkpoint operation to occur. Checkpoints can also happen at other times when transactions are committed. The bigger the WAL file, the longer a checkpoint operation takes, so we try to keep the WAL file relatively small to avoid long delays. The size of the WAL file is also constrained by 'db_journal_size_limit'.

getWALConnectionPoolSize

public static int getWALConnectionPoolSize()

Gets the connection pool size when in WAL mode. Maximum number of database connections opened and managed by framework layer to handle queries on each database when using Write-Ahead Logging.