Package com.google.cloud.spanner.watcher

Class SpannerUtils

java.lang.Object

com.google.cloud.spanner.watcher.SpannerUtils

@InternalApi("Public visibility for re-use by other spanner-change-watcher libraries. API-breaking changes without prior notice is possible.")
public class SpannerUtils
extends Object

Utils for getting commonly needed schema information from a Spanner database.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SpannerUtils.LogRecordBuilder

Field Summary

Fields

Modifier and Type	Field	Description
static String	FIND_COMMIT_TIMESTAMP_COLUMN_QUERY	Query for getting the column of a table that holds the commit timestamp.

Constructor Summary

Constructors

Constructor	Description
SpannerUtils()

Method Summary

Modifier and Type	Method	Description
static com.google.cloud.spanner.Key	buildKey(Iterable<String> pkColumns, com.google.cloud.spanner.ResultSet rs)	Creates a Key instance from an Iterable of primary key columns and a ResultSet containing the data to use for the key.
static com.google.api.core.ApiFuture<String>	getIndexOnColumn(com.google.cloud.spanner.DatabaseClient client, TableId table, String column)	Returns any (secondary) index that is defined on only the given column.
static com.google.api.core.ApiFuture<List<String>>	getPrimaryKeyColumns(com.google.cloud.spanner.DatabaseClient client, TableId table)	Returns the primary key columns of a table.
static com.google.api.core.ApiFuture<String>	getTimestampColumn(com.google.cloud.spanner.DatabaseClient client, TableId table)	Returns the name of the commit timestamp column of the given table.

Methods inherited from class java.lang.Object

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

Field Detail

FIND_COMMIT_TIMESTAMP_COLUMN_QUERY

public static final String FIND_COMMIT_TIMESTAMP_COLUMN_QUERY

Query for getting the column of a table that holds the commit timestamp.

See Also:

Constant Field Values

Constructor Detail

SpannerUtils

public SpannerUtils()

Method Detail

getTimestampColumn

@InternalApi
public static com.google.api.core.ApiFuture<String> getTimestampColumn(com.google.cloud.spanner.DatabaseClient client,
                                                                       TableId table)

Returns the name of the commit timestamp column of the given table.

getPrimaryKeyColumns

@InternalApi
public static com.google.api.core.ApiFuture<List<String>> getPrimaryKeyColumns(com.google.cloud.spanner.DatabaseClient client,
                                                                               TableId table)

Returns the primary key columns of a table.

getIndexOnColumn

@InternalApi
public static com.google.api.core.ApiFuture<String> getIndexOnColumn(com.google.cloud.spanner.DatabaseClient client,
                                                                     TableId table,
                                                                     String column)

Returns any (secondary) index that is defined on only the given column. Any such index can be used by SpannerTableChangeWatchers that do not use any ShardProviders, and therefore only search for changes by filtering directly on the commit timestamp column. These indexes can cause write hotspots in a Cloud Spanner database, but for tables that do not receive a large number of writes, this does not necessarily need to be a problem. This function will prefer null-filtered indexes over non-null-filtered indexes. Other than that, the index that is returned by this function when there are multiple indexes defined on only this column is undefined.

buildKey

@InternalApi
public static com.google.cloud.spanner.Key buildKey(Iterable<String> pkColumns,
                                                    com.google.cloud.spanner.ResultSet rs)

Creates a Key instance from an Iterable of primary key columns and a ResultSet containing the data to use for the key.