Split into Maven multi-module (engine + server); rename to cuckooDB

.github/workflows/ci.yml

@@ -28,3 +28,4 @@ jobs:
         uses: codecov/codecov-action@v5
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
+          files: engine/target/site/jacoco/jacoco.xml

.gitignore

@@ -1,12 +1,18 @@
 target/
 *.iml
+
+# Eclipse / JDT.LS metadata
+.classpath
+.project
+.settings/
 .DS_Store
 *.class
 .omo/
-src/test/resources/test_integration_output/
-src/test/resources/test_sample_output/
-src/test/resources/test_integration_queries/
+engine/src/test/resources/test_integration_output/
+engine/src/test/resources/test_sample_output/
+engine/src/test/resources/test_integration_queries/
 
 # local working files
 dev/
 CLAUDE.md
+REPORT_*.md

BENCHMARK_RESULTS.md

@@ -2,7 +2,7 @@
 
 ## Overview
 
-This document contains quantifiable performance results from the query optimization benchmark suite added to BlazeDB. The benchmarks measure tuple processing reduction achieved by rule-based query optimizations.
+This document contains quantifiable performance results from the query optimization benchmark suite added to CuckooDB. The benchmarks measure tuple processing reduction achieved by rule-based query optimizations.
 
 ## Benchmark Methodology
 

README.md

@@ -1,4 +1,4 @@
-# Java Query Engine
+# cuckooDB
 
 ![CI](https://github.com/JinBa1/java-query-engine/actions/workflows/ci.yml/badge.svg)
 ![Coverage](https://codecov.io/gh/JinBa1/java-query-engine/branch/main/graph/badge.svg)
@@ -83,15 +83,15 @@ The focus is on demonstrating query planning, optimisation, and the Volcano iter
 git clone https://github.com/JinBa1/java-query-engine.git
 cd java-query-engine
 
-# Build fat JAR
-./mvnw clean compile assembly:single
+# Build fat JAR (engine module)
+./mvnw -pl engine -DskipTests clean package
 ```
 
 **Run a query:**
 
 ```bash
-java -cp target/java-query-engine-1.0.0-jar-with-dependencies.jar \
-  com.github.jinba1.blazedb.BlazeDB \
+java -cp engine/target/cuckoodb-engine-1.0.0-jar-with-dependencies.jar \
+  com.github.jinba1.cuckoodb.CuckooDB \
   database_dir input_file output_file [--max-tuples=N] [--timeout-ms=N]
 ```
 
@@ -159,10 +159,10 @@ The engine supports two join algorithms; the planner selects between them automa
 
 ### Benchmarks
 
-Performance was measured with a JMH 1.37 benchmark suite in the `bench/` package (`src/test/java/com/github/jinba1/blazedb/bench/`). The suite is compiled in CI but never run there; run it locally with:
+Performance was measured with a JMH 1.37 benchmark suite in the `bench/` package (`engine/src/test/java/com/github/jinba1/cuckoodb/bench/`). The suite is compiled in CI but never run there; run it locally with:
 
 ```bash
-./mvnw -q test-compile exec:exec -Dexec.executable=java -Dexec.classpathScope=test \
+./mvnw -pl engine -q test-compile exec:exec -Dexec.executable=java -Dexec.classpathScope=test \
   "-Dexec.args=-cp %classpath org.openjdk.jmh.Main .*Benchmark"
 ```
 
@@ -187,7 +187,7 @@ Benchmarks are compiled in CI but never executed there.
 
 ## Demo
 
-**Input table** (`samples/db/data/Student.csv`):
+**Input table** (`engine/samples/db/data/Student.csv`):
 
 ```
 A, B, C, D
@@ -199,7 +199,7 @@ A, B, C, D
 6, 300, 400, 11
 ```
 
-**Query** (`samples/input/query4.sql`):
+**Query** (`engine/samples/input/query4.sql`):
 
 ```sql
 SELECT * FROM Student WHERE Student.A < 3;
@@ -208,17 +208,17 @@ SELECT * FROM Student WHERE Student.A < 3;
 **Command:**
 
 ```bash
-java -cp target/java-query-engine-1.0.0-jar-with-dependencies.jar \
-  com.github.jinba1.blazedb.BlazeDB \
-  samples/db samples/input/query4.sql output.csv
+java -cp engine/target/cuckoodb-engine-1.0.0-jar-with-dependencies.jar \
+  com.github.jinba1.cuckoodb.CuckooDB \
+  engine/samples/db engine/samples/input/query4.sql output.csv
 ```
 
 To limit resource usage, add optional budget flags:
 
 ```bash
-java -cp target/java-query-engine-1.0.0-jar-with-dependencies.jar \
-  com.github.jinba1.blazedb.BlazeDB \
-  samples/db samples/input/query4.sql output.csv --max-tuples=10000 --timeout-ms=5000
+java -cp engine/target/cuckoodb-engine-1.0.0-jar-with-dependencies.jar \
+  com.github.jinba1.cuckoodb.CuckooDB \
+  engine/samples/db engine/samples/input/query4.sql output.csv --max-tuples=10000 --timeout-ms=5000
 ```
 
 **Output** (`output.csv`):
@@ -231,15 +231,24 @@ a,b,c,d
 
 ## Running Examples
 
-The `samples/` directory ships with 20 queries and a small dataset (Student, Course, Enrolled, Staff tables). Expected output lives in `samples/expected_output/`.
+The `engine/samples/` directory ships with 20 queries and a small dataset (Student, Course, Enrolled, Staff tables). Expected output lives in `engine/samples/expected_output/`.
+
+Run all 20 through the bundled runner, which diffs each result against the expected output and reports pass/fail. It is launched via `exec:exec` (not `exec:java`) so it runs with the engine module as the working directory — `exec:java` would keep the working directory at the reactor root and fail to find `samples/`:
+
+```bash
+./mvnw -pl engine -q test-compile exec:exec -Dexec.executable=java -Dexec.classpathScope=test \
+  "-Dexec.args=-cp %classpath com.github.jinba1.cuckoodb.SampleQueryRunner"
+```
+
+Or run each query through the CLI and diff manually:
 
 ```bash
 # Run all sample queries and diff against expected output
 for i in $(seq 1 20); do
-  java -cp target/java-query-engine-1.0.0-jar-with-dependencies.jar \
-    com.github.jinba1.blazedb.BlazeDB \
-    samples/db "samples/input/query${i}.sql" "/tmp/out${i}.csv"
-  diff "samples/expected_output/query${i}.csv" "/tmp/out${i}.csv" && echo "query${i}: OK"
+  java -cp engine/target/cuckoodb-engine-1.0.0-jar-with-dependencies.jar \
+    com.github.jinba1.cuckoodb.CuckooDB \
+    engine/samples/db "engine/samples/input/query${i}.sql" "/tmp/out${i}.csv"
+  diff "engine/samples/expected_output/query${i}.csv" "/tmp/out${i}.csv" && echo "query${i}: OK"
 done
 ```
 
@@ -254,15 +263,20 @@ The test suite covers individual operators, the query planner, the optimiser, ex
 ## Project Structure
 
 ```
-├── src/main/java/com/github/jinba1/blazedb/   # Core engine (35 files)
-│   └── operator/                                # Volcano operators (11 files, incl. HashJoinOperator)
-├── src/test/java/com/github/jinba1/blazedb/    # JUnit 5 tests (339 tests across 33 files)
-├── samples/
-│   ├── db/data/                                 # CSV data files (header row + data rows)
-│   ├── input/query[1-20].sql                    # Sample queries
-│   └── expected_output/query[1-20].csv          # Expected results
-├── pom.xml                                      # Maven config (Java 17, JSqlParser 4.7, commons-csv 1.14.1, JMH 1.37 test-scope)
-├── mvnw / mvnw.cmd                              # Maven Wrapper
+├── pom.xml                                          # Parent POM (aggregator: engine + server; Java 17, dep/plugin management)
+├── engine/                                          # Pure query engine — zero Spring dependencies
+│   ├── pom.xml                                      # cuckoodb-engine (JSqlParser 4.7, commons-csv 1.14.1, JMH 1.37 test-scope)
+│   ├── src/main/java/com/github/jinba1/cuckoodb/    # Core engine (35 files)
+│   │   └── operator/                                # Volcano operators (11 files, incl. HashJoinOperator)
+│   ├── src/test/java/com/github/jinba1/cuckoodb/    # JUnit 5 tests (339 tests across 33 files)
+│   └── samples/
+│       ├── db/data/                                 # CSV data files (header row + data rows)
+│       ├── input/query[1-20].sql                    # Sample queries
+│       └── expected_output/query[1-20].csv          # Expected results
+├── server/                                          # REST gateway skeleton — Spring Boot REST gateway planned
+│   ├── pom.xml                                      # cuckoodb-server (depends on cuckoodb-engine; no Spring yet)
+│   └── src/main/java/com/github/jinba1/cuckoodb/server/
+├── mvnw / mvnw.cmd                                  # Maven Wrapper
 └── LICENSE
 ```
 

engine/pom.xml

@@ -0,0 +1,123 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>com.github.jinba1</groupId>
+    <artifactId>cuckoodb-parent</artifactId>
+    <version>1.0.0</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+
+  <artifactId>cuckoodb-engine</artifactId>
+  <packaging>jar</packaging>
+
+  <name>cuckooDB Engine</name>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.github.jsqlparser</groupId>
+      <artifactId>jsqlparser</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-csv</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.openjdk.jmh</groupId>
+      <artifactId>jmh-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.openjdk.jmh</groupId>
+      <artifactId>jmh-generator-annprocess</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <testAnnotationProcessorPaths>
+            <path>
+              <groupId>org.openjdk.jmh</groupId>
+              <artifactId>jmh-generator-annprocess</artifactId>
+              <version>${jmh.version}</version>
+            </path>
+          </testAnnotationProcessorPaths>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>run-cuckoodb</id>
+            <goals>
+              <goal>java</goal>
+            </goals>
+            <configuration>
+              <mainClass>com.github.jinba1.cuckoodb.CuckooDB</mainClass>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <configuration>
+          <archive>
+            <manifest>
+              <mainClass>com.github.jinba1.cuckoodb.CuckooDB</mainClass>
+            </manifest>
+          </archive>
+          <descriptorRefs>
+            <descriptorRef>jar-with-dependencies</descriptorRef>
+          </descriptorRefs>
+        </configuration>
+        <executions>
+          <execution>
+            <id>make-assembly</id>
+            <phase>package</phase>
+            <goals>
+              <goal>single</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.jacoco</groupId>
+        <artifactId>jacoco-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <goals>
+              <goal>prepare-agent</goal>
+            </goals>
+          </execution>
+          <execution>
+            <id>report</id>
+            <phase>test</phase>
+            <goals>
+              <goal>report</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/main/java/com/github/jinba1/blazedb/AggregateCall.java → engine/src/main/java/com/github/jinba1/cuckoodb/AggregateCall.java

@@ -1,4 +1,4 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 import net.sf.jsqlparser.expression.Expression;
 

src/main/java/com/github/jinba1/blazedb/AggregateFunction.java → engine/src/main/java/com/github/jinba1/cuckoodb/AggregateFunction.java

@@ -1,4 +1,4 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 /**
  * The aggregate functions supported in SELECT lists.

src/main/java/com/github/jinba1/blazedb/ColumnExtractor.java → engine/src/main/java/com/github/jinba1/cuckoodb/ColumnExtractor.java

@@ -1,4 +1,4 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 import net.sf.jsqlparser.expression.ExpressionVisitorAdapter;
 import net.sf.jsqlparser.schema.Column;

src/main/java/com/github/jinba1/blazedb/ColumnIdentity.java → engine/src/main/java/com/github/jinba1/cuckoodb/ColumnIdentity.java

@@ -1,4 +1,4 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 import net.sf.jsqlparser.schema.Column;
 

src/main/java/com/github/jinba1/blazedb/ColumnType.java → engine/src/main/java/com/github/jinba1/cuckoodb/ColumnType.java

@@ -1,4 +1,4 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 /** The data type of a table column. */
 public enum ColumnType { INT, STRING }

src/main/java/com/github/jinba1/blazedb/ConditionSplitter.java → engine/src/main/java/com/github/jinba1/cuckoodb/ConditionSplitter.java

@@ -1,4 +1,4 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 import net.sf.jsqlparser.expression.BinaryExpression;
 import net.sf.jsqlparser.expression.Expression;

src/main/java/com/github/jinba1/blazedb/Constants.java → engine/src/main/java/com/github/jinba1/cuckoodb/Constants.java

@@ -1,7 +1,7 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 /**
- * Defines global constants used throughout the BlazeDB system.
+ * Defines global constants used throughout the CuckooDB system.
  * This class contains application-wide constants to ensure consistency
  * and reduce duplication across the codebase. These include file and directory names,
  * schema prefixes, and other string literals used for database operations.

src/main/java/com/github/jinba1/blazedb/BlazeDB.java → engine/src/main/java/com/github/jinba1/cuckoodb/CuckooDB.java

@@ -1,4 +1,4 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 import java.io.*;
 import java.nio.file.Files;
@@ -9,14 +9,14 @@
 import org.apache.commons.csv.CSVFormat;
 import org.apache.commons.csv.CSVPrinter;
 
-import com.github.jinba1.blazedb.operator.LimitOperator;
-import com.github.jinba1.blazedb.operator.Operator;
+import com.github.jinba1.cuckoodb.operator.LimitOperator;
+import com.github.jinba1.cuckoodb.operator.Operator;
 
 /**
  * Lightweight in-memory relational query engine.
  * CLI interface: database_dir input_file output_file [--max-tuples=N] [--timeout-ms=N]
  */
-public class BlazeDB {
+public class CuckooDB {
 	public static void main(String[] args) {
 		int code = run(args);
 		if (code != 0) {
@@ -99,7 +99,7 @@ static int run(String[] args) {
 
 	private static void usage() {
 		System.err.println(
-				"Usage: BlazeDB database_dir input_file output_file [--max-tuples=N] [--timeout-ms=N]");
+				"Usage: CuckooDB database_dir input_file output_file [--max-tuples=N] [--timeout-ms=N]");
 	}
 
 	/**

src/main/java/com/github/jinba1/blazedb/DBCatalog.java → engine/src/main/java/com/github/jinba1/cuckoodb/DBCatalog.java

@@ -1,4 +1,4 @@
-package com.github.jinba1.blazedb;
+package com.github.jinba1.cuckoodb;
 
 import org.apache.commons.csv.CSVFormat;
 import org.apache.commons.csv.CSVParser;
@@ -13,7 +13,7 @@
 import java.util.stream.Stream;
 
 /**
- * The DBCatalog class serves as a central repository for durable database metadata in BlazeDB.
+ * The DBCatalog class serves as a central repository for durable database metadata in CuckooDB.
  * It implements the singleton pattern to ensure a single, consistent view of database structure
  * across all components of the system.
  * This class maintains information about: