diff --git a/.travis.yml b/.travis.yml
index 1ccd703..e622e12 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,5 +29,11 @@ compiler:
 
 script:
   - make cleanall
-  - make
+  - make -j4
+
   - make test
+  - make test_format
+  - make test_example
+
+  # Test if benchmark can be built.
+  # - make build_benchmark
diff --git a/Makefile b/Makefile
index 4bf9c0e..cb55818 100644
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,9 @@
-# directories
+# Directories.
 BIN        = bin
 SRC        = src
 SRCPARSER  = src/parser
 
-# files
+# Files.
 PARSERCPP   = $(SRCPARSER)/bison_parser.cpp $(SRCPARSER)/flex_lexer.cpp
 LIBCPP      = $(shell find $(SRC) -name '*.cpp' -not -path "$(SRCPARSER)/*") $(PARSERCPP)
 LIBOBJ      = $(LIBCPP:%.cpp=%.o)
@@ -11,44 +11,54 @@ TESTCPP     = $(shell find test/ -name '*.cpp')
 
 ALLLIB      = $(shell find $(SRC) -name '*.cpp' -not -path "$(SRCPARSER)/*") $(shell find $(SRC) -name '*.h' -not -path "$(SRCPARSER)/*")
 ALLTEST     = $(shell find test/ -name '*.cpp') $(shell find test/ -name '*.h')
+EXAMPLESRC  = $(shell find example/ -name '*.cpp') $(shell find example/ -name '*.h')
 
-# compile & link flages
-CFLAGS     = -std=c++11 -Wall -fPIC -g
+# Compiler & linker flags.
+CFLAGS     = -std=c++11 -Wall -fPIC
 LIBFLAGS   = -shared
 TARGET     = libsqlparser.so
 INSTALL    = /usr/local
 
-CTESTFLAGS = -Wall -Isrc/ -Itest/ -L./ -std=c++11 -lstdc++ -g
+CTESTFLAGS = -Wall -Isrc/ -Itest/ -L./ -std=c++11 -lstdc++ -O3
+
+# Set compile mode to -g or -O3.
+mode ?= release
+ifeq ($(mode), debug)
+	CFLAGS += -g
+else
+	CFLAGS += -O3
+endif
+
+GMAKE = make mode=$(mode)
 
 all: library
 
 library: $(TARGET)
 
 $(TARGET): $(LIBOBJ)
+	echo $(mode)
 	$(CXX) $(LIBFLAGS) -o $(TARGET) $(LIBOBJ)
 
-$(SRCPARSER)/flex_lexer.o: $(SRCPARSER)/flex_lexer.cpp
+$(SRCPARSER)/flex_lexer.o: $(SRCPARSER)/flex_lexer.cpp $(SRCPARSER)/bison_parser.cpp
 	$(CXX) $(CFLAGS) -c -o $@ $< -Wno-sign-compare -Wno-unneeded-internal-declaration -Wno-deprecated-register
 
 %.o: %.cpp $(PARSERCPP)
 	$(CXX) $(CFLAGS) -c -o $@ $<
 
 $(SRCPARSER)/bison_parser.cpp: $(SRCPARSER)/bison_parser.y
-	make -C $(SRCPARSER)/ bison_parser.cpp
+	$(GMAKE) -C $(SRCPARSER)/ bison_parser.cpp
 
 $(SRCPARSER)/flex_lexer.cpp: $(SRCPARSER)/flex_lexer.l
-	make -C $(SRCPARSER)/ flex_lexer.cpp
-
-parser:
-	make -C $(SRCPARSER) all
+	$(GMAKE) -C $(SRCPARSER)/ flex_lexer.cpp
 
 clean:
 	rm -f $(TARGET)
 	rm -rf $(BIN)
 	find $(SRC) -type f -name '*.o' -delete
+	$(GMAKE) -C benchmark/ clean
 
 cleanparser:
-	make -C $(SRCPARSER)/ clean
+	$(GMAKE) -C $(SRCPARSER)/ clean
 
 cleanall: clean cleanparser
 
@@ -58,12 +68,15 @@ install:
 	cp -r src $(INSTALL)/include/hsql
 	find $(INSTALL)/include/hsql -not -name '*.h' -type f | xargs rm
 
-format:
-	astyle --options=astyle.options $(ALLLIB)
-	astyle --options=astyle.options $(ALLTEST)
+#################
+### Benchmark ###
+#################
 
-run_benchmark:
-	make -C benchmark/ clean run
+benchmark: library
+	$(GMAKE) -C benchmark/ clean run
+
+build_benchmark: library
+	$(GMAKE) -C benchmark/ parser_benchmark
 
 ############
 ### Test ###
@@ -72,11 +85,26 @@ run_benchmark:
 test: $(BIN)/sql_tests
 	bash test/test.sh
 
-# test whete
-test_install:
-	make -C example/
-	./example/example "SELECT * FROM students WHERE name = 'Max Mustermann';"
+test_example:
+	$(GMAKE) -C example/
+	LD_LIBRARY_PATH=./ \
+	  ./example/example "SELECT * FROM students WHERE name = 'Max Mustermann';"
+
+test_format:
+	@! astyle --options=astyle.options $(ALLLIB) | grep -q "Formatted"
+	@! astyle --options=astyle.options $(ALLTEST) | grep -q "Formatted"
 
 $(BIN)/sql_tests: library
 	@mkdir -p $(BIN)/
 	$(CXX) $(CTESTFLAGS) $(TESTCPP) -o $(BIN)/sql_tests -lsqlparser
+
+
+############
+### Misc ###
+############
+
+format:
+	astyle --options=astyle.options $(ALLLIB)
+	astyle --options=astyle.options $(ALLTEST)
+	astyle --options=astyle.options $(EXAMPLESRC)
+
diff --git a/benchmark/Makefile b/benchmark/Makefile
index a33b9d4..c5564a3 100644
--- a/benchmark/Makefile
+++ b/benchmark/Makefile
@@ -2,12 +2,13 @@
 SRC = ./
 CPP  = $(shell find $(SRC) -name '*.cpp')
 
-CFLAGS = -std=c++11 -lstdc++ -Wall -I../src/ -L../
+CFLAGS = -std=c++11 -lstdc++ -Wall -I../src/ -L../ -O3
 
 all: parser_benchmark
 
 run: parser_benchmark
-	@export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:../ && ./parser_benchmark
+	@export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:../ &&\
+		./parser_benchmark
 
 parser_benchmark: $(CPP)
 	$(CXX) $(CFLAGS) $(CPP) -o parser_benchmark -lbenchmark -lpthread -lsqlparser
diff --git a/benchmark/parser_benchmark.cpp b/benchmark/parser_benchmark.cpp
index cea4709..e42edda 100644
--- a/benchmark/parser_benchmark.cpp
+++ b/benchmark/parser_benchmark.cpp
@@ -10,12 +10,39 @@
 #include "benchmark_utils.h"
 
 
-PARSE_QUERY_BENCHMARK(BM_SimpleSelect,
+PARSE_QUERY_BENCHMARK(BM_Q1SimpleSelect,
   "SELECT * FROM test;");
 
-PARSE_QUERY_BENCHMARK(BM_SimpleSubSelect,
-  "SELECT age, street AS address FROM (SELECT * FROM data);");
+PARSE_QUERY_BENCHMARK(BM_Q2SimpleSubSelect,
+  "SELECT a, b AS address FROM (SELECT * FROM test WHERE c < 100 AND b > 3) t1 WHERE a < 10 AND b < 100;");
 
+PARSE_QUERY_BENCHMARK(BM_Q3SingleJoin,
+  "SELECT \"left\".a, \"left\".b, \"right\".a, \"right\".b FROM table_a AS \"left\" JOIN table_b AS \"right\" ON \"left\".a = \"right\".a;");
+
+PARSE_QUERY_BENCHMARK(BM_Q4TPCHQuery,
+"SELECT"
+"  l_orderkey,"
+"  SUM(l_extendedprice * (1 - l_discount)) AS revenue,"
+"    o_orderdate,"
+"    o_shippriority"
+"  FROM"
+"    customer,"
+"    orders,"
+"    lineitem"
+"  WHERE"
+"    c_mktsegment = '%s'"
+"    and c_custkey = o_custkey"
+"    and l_orderkey = o_orderkey"
+"    and o_orderdate < '%s'"
+"    and l_shipdate > '%s'"
+"  GROUP BY"
+"    l_orderkey,"
+"    o_orderdate,"
+"    o_shippriority"
+"  ORDER BY"
+"    revenue DESC,"
+"    o_orderdate;"
+  );
 PARSE_QUERY_BENCHMARK(BM_TwoSelects,
   "SELECT * FROM test; SELECT age, street AS address FROM data;");
 
diff --git a/example/example.cpp b/example/example.cpp
index 9961d3d..7cf0817 100644
--- a/example/example.cpp
+++ b/example/example.cpp
@@ -8,34 +8,34 @@
 // contains printing utilities
 #include "util/sqlhelper.h"
 
-int main(int argc, char *argv[]) {
-    if (argc <= 1) {
-        fprintf(stderr, "Usage: ./example \"SELECT * FROM test;\"\n");
-        return -1;
-    }
-    std::string query = argv[1];
-
-    // parse a given query
-    hsql::SQLParserResult result;
-    hsql::SQLParser::parseSQLString(query, &result);
-
-    // check whether the parsing was successful
-
-    if (result.isValid()) {
-        printf("Parsed successfully!\n");
-        printf("Number of statements: %lu\n", result.size());
-
-        for (uint i = 0; i < result.size(); ++i) {
-            // Print a statement summary.
-            hsql::printStatementInfo(result.getStatement(i));
-        }
-        return 0;
-    } else {
-        fprintf(stderr, "Given string is not a valid SQL query.\n");
-        fprintf(stderr, "%s (L%d:%d)\n", 
-                result.errorMsg(),
-                result.errorLine(),
-                result.errorColumn());
-        return -1;
+int main(int argc, char* argv[]) {
+  if (argc <= 1) {
+    fprintf(stderr, "Usage: ./example \"SELECT * FROM test;\"\n");
+    return -1;
+  }
+  std::string query = argv[1];
+
+  // parse a given query
+  hsql::SQLParserResult result;
+  hsql::SQLParser::parseSQLString(query, &result);
+
+  // check whether the parsing was successful
+
+  if (result.isValid()) {
+    printf("Parsed successfully!\n");
+    printf("Number of statements: %lu\n", result.size());
+
+    for (uint i = 0; i < result.size(); ++i) {
+      // Print a statement summary.
+      hsql::printStatementInfo(result.getStatement(i));
     }
+    return 0;
+  } else {
+    fprintf(stderr, "Given string is not a valid SQL query.\n");
+    fprintf(stderr, "%s (L%d:%d)\n",
+            result.errorMsg(),
+            result.errorLine(),
+            result.errorColumn());
+    return -1;
+  }
 }