merge: Add support for SQL via Apache Calcite (#78)

This pull request integrates initial support for SQL queries via Apache Calcite into the OpenDC codebase. 
Our vision is that users of OpenDC should be able to use SQL queries to access and process most 
of the experiment data generated by simulations.

This pull request moves towards this goal by adding the ability to query workload traces supported 
by OpenDC using SQL. We also provide a CLI for querying the data in workload traces via `opendc-trace-tools`:

```bash
opendc-trace-tools query -i data/bitbrains-small  -f opendc-vm "SELECT MAX(cpu_count) FROM resource_states"
```

## Implementation Notes :hammer_and_pick:

* Add Calcite (SQL) integration
* Add support for writing via SQL 
* Add support for writing via SQL 
* Support custom Parquet ReadSupport implementations
* Read records using low-level Parquet API 
* Do not use Avro when exporting experiment data
* Do not use Avro when reading WTF trace
* Drop dependency on Avro
* Add support for projections

## External Dependencies :four_leaf_clover:

* Apache Calcite

## Breaking API Changes :warning:

* The existing code for reading Parquet traces using Apache Avro has been removed.
* `TraceFormat.newReader` now accepts a nullable `projection` parameter 

1 files changed, 3 insertions, 1 deletions

diff --git a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/spi/TraceFormat.kt b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/spi/TraceFormat.kt
index f2e610db..47761e0f 100644
--- a/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/spi/TraceFormat.kt
+++ b/opendc-trace/opendc-trace-api/src/main/kotlin/org/opendc/trace/spi/TraceFormat.kt
@@ -22,6 +22,7 @@
 
 package org.opendc.trace.spi
 
+import org.opendc.trace.TableColumn
 import org.opendc.trace.TableReader
 import org.opendc.trace.TableWriter
 import java.nio.file.Path
@@ -68,10 +69,11 @@ public interface TraceFormat {
      *
      * @param path The path to the trace to open.
      * @param table The name of the table to open a [TableReader] for.
+     * @param projection The list of [TableColumn]s to project or `null` if no projection is performed.
      * @throws IllegalArgumentException If [table] does not exist.
      * @return A [TableReader] instance for the table.
      */
-    public fun newReader(path: Path, table: String): TableReader
+    public fun newReader(path: Path, table: String, projection: List<TableColumn<*>>?): TableReader
 
     /**
      * Open a [TableWriter] for the specified [table].