fix(pgwire) Rudimentary support for COPY FROM via pgwire (#2061)

core/src/main/java/io/questdb/cutlass/pgwire/PGConnectionContext.java

@@ -1844,7 +1844,6 @@ public class PGConnectionContext implements IOContext, Mutable, WriterSource {
             case CompiledQuery.COPY_LOCAL:
                 // uncached
                 queryTag = TAG_COPY;
-                sendCopyInResponse(compiler.getEngine(), cq.getTextLoader());
                 break;
             case CompiledQuery.SET:
                 queryTag = TAG_SET;
@@ -2213,6 +2212,9 @@ public class PGConnectionContext implements IOContext, Mutable, WriterSource {
         responseAsciiSink.reset();
     }
 
+    // This method is currently unused. it's used for the COPY sub-protocol, which is currently not implemented.
+    // It's left here so when we add the sub-protocol later we won't need to reimplemented it.
+    // We could keep it just in git history, but chances are nobody would recall to search for it there
     private void sendCopyInResponse(CairoEngine engine, TextLoader textLoader) throws PeerDisconnectedException, PeerIsSlowToReadException {
         if (
                 TableUtils.TABLE_EXISTS == engine.getStatus(

core/src/test/java/io/questdb/cutlass/pgwire/PGJobContextTest.java

@@ -62,6 +62,7 @@ import org.postgresql.core.BaseConnection;
 import org.postgresql.util.PGTimestamp;
 import org.postgresql.util.PSQLException;
 
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.sql.Date;
@@ -93,6 +94,7 @@ public class PGJobContextTest extends BasePGTest {
 
     @BeforeClass
     public static void init() {
+        inputRoot = new File(".").getAbsolutePath();
         final SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss'.0'");
         formatter.setTimeZone(TimeZone.getTimeZone("UTC"));
         final Stream<Object[]> dates = LongStream.rangeClosed(0, count - 1)
@@ -1679,6 +1681,25 @@ public class PGJobContextTest extends BasePGTest {
         }
     }
 
+    @Test
+    public void testLocalCopyFrom() throws Exception {
+        try (final PGWireServer ignored = createPGServer(2);
+             final Connection connection = getConnection(false, true);
+             final PreparedStatement copyStatement = connection.prepareStatement("copy testLocalCopyFrom from '/src/test/resources/csv/test-numeric-headers.csv' with header true")) {
+
+            copyStatement.execute();
+
+            try (final PreparedStatement selectStatement = connection.prepareStatement("select * FROM testLocalCopyFrom");
+                 final ResultSet rs = selectStatement.executeQuery()) {
+                sink.clear();
+                assertResultSet("type[VARCHAR],value[VARCHAR],active[VARCHAR],desc[VARCHAR],_1[INTEGER]\n"
+                        + "ABC,xy,a,brown fox jumped over the fence,10\n"
+                        + "CDE,bb,b,sentence 1\n"
+                        + "sentence 2,12\n", sink, rs);
+            }
+        }
+    }
+
     @Test
     public void testCursorFetch() throws Exception {
         assertMemoryLeak(() -> {