From 670cd279ea7789e07b6d778a21fdec68347ab305 Mon Sep 17 00:00:00 2001 From: Fabian Mastenbroek Date: Mon, 2 May 2022 14:17:55 +0200 Subject: feat(trace/api): Add support for projecting tables This change adds support for projecting certain columns of a table. This enables faster reading for tables with high number of columns. Currently, we support projection in the Parquet-based workload formats. Other formats are text-based and will probably not benefit much from projection. --- .../opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt') diff --git a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt index b0181cbc..05d0234a 100644 --- a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt +++ b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/Table.kt @@ -42,9 +42,11 @@ public interface Table { public val partitionKeys: List> /** - * Open a [TableReader] for this table. + * Open a [TableReader] for a projection of this table. + * + * @param projection The list of columns to fetch from the table or `null` if no projection is performed. */ - public fun newReader(): TableReader + public fun newReader(projection: List>? = null): TableReader /** * Open a [TableWriter] for this table. -- cgit v1.2.3