Address review feedback: AIX default, log level, stale tests

- AIX/PowerPC: default to Arrow disabled (was enabled). Honour explicit
  EnableArrow=1 if user sets it. Added isAixOrPowerPc() helper.
- Restore client-type guard for AIX — prevents routing to SEA when
  Arrow is disabled on AIX.
- Log deprecation at INFO (not WARN) — logged once at connection init,
  not per statement.
- Updated changelog to mention PowerPC architectures explicitly.
- Renamed stale/contradictory tests:
  testClientTypeWhenArrowDisabled → clarified as non-AIX behavior
  testJsonInlineChunkedResults_withoutArrow → deprecated flag test
- Added 2 new tests: default Arrow=true, explicit disable ignored.

Co-authored-by: Isaac
Signed-off-by: Gopal Lal <gopal.lal@databricks.com>

Author: gopalldb

NEXT_CHANGELOG.md

@@ -12,7 +12,7 @@
 
 4. **Native geospatial type support (`GEOMETRY` and `GEOGRAPHY`) is now enabled by default.** `getObject()` now returns `IGeometry`/`IGeography` instances instead of EWKT strings. Set `EnableGeoSpatialSupport=0` to restore the previous behavior.
 
-5. **`EnableArrow` connection property is deprecated and ignored.** Arrow serialization is now always enabled. Setting `EnableArrow=0` previously disabled Arrow and forced columnar/JSON inline results; this value is now ignored and a deprecation warning is logged. For JSON inline results with SEA, disable CloudFetch via `EnableQueryResultDownload=0`. The only exception is AIX platforms, where `EnableArrow` is still honoured due to known Arrow native library compatibility issues.
+5. **`EnableArrow` connection property is deprecated and ignored.** Arrow serialization is now always enabled. Setting `EnableArrow=0` previously disabled Arrow and forced columnar/JSON inline results; this value is now ignored and a deprecation warning is logged. For JSON inline results with SEA, disable CloudFetch via `EnableQueryResultDownload=0`. Exception: on AIX platforms and PowerPC architectures (`os.arch` contains `ppc`), `EnableArrow` is still honoured and defaults to disabled due to known Arrow native library compatibility issues.
 
 ### Added
 

src/main/java/com/databricks/jdbc/api/impl/DatabricksConnectionContext.java

@@ -505,6 +505,10 @@ public DatabricksClientType getClientTypeFromContext() {
           remainingMs);
       return DatabricksClientType.THRIFT;
     }
+    // On AIX/PowerPC, Arrow may be disabled — check before routing to SEA
+    if (isAixOrPowerPc() && !shouldEnableArrow()) {
+      return DatabricksClientType.THRIFT;
+    }
     // Check if CloudFetch is disabled - Thrift is required for inline mode
     if (!isCloudFetchEnabled()) {
       return DatabricksClientType.THRIFT;
@@ -668,17 +672,20 @@ public Boolean shouldEnableArrow() {
     // Arrow is always enabled unless running on AIX or IBM Power (which have known
     // issues with the Arrow native library). The EnableArrow connection property is
     // deprecated and its value is ignored on non-AIX/IBM platforms.
-    String osName = System.getProperty("os.name", "").toLowerCase();
-    String osArch = System.getProperty("os.arch", "").toLowerCase();
-    if (osName.contains("aix") || osArch.contains("ppc")) {
-      // On AIX/IBM Power, honour the user's explicit setting (default is "1" = enabled)
-      return Objects.equals(getParameter(DatabricksJdbcUrlParams.ENABLE_ARROW), "1");
+    if (isAixOrPowerPc()) {
+      // On AIX/PowerPC, Arrow native library has known issues — default to disabled.
+      // Honour explicit EnableArrow=1 if user sets it.
+      String explicitValue = getParameterIgnoreDefault(DatabricksJdbcUrlParams.ENABLE_ARROW);
+      if (explicitValue != null) {
+        return explicitValue.equals("1");
+      }
+      return false; // default disabled on AIX/PowerPC
     }
 
-    // Log deprecation warning if user explicitly set EnableArrow=0 (ignored)
+    // Log deprecation warning once if user explicitly set EnableArrow=0 (ignored)
     String explicitValue = getParameterIgnoreDefault(DatabricksJdbcUrlParams.ENABLE_ARROW);
     if (explicitValue != null && explicitValue.equals("0")) {
-      LOGGER.warn(
+      LOGGER.info(
           "EnableArrow=0 is deprecated and ignored. Arrow serialization is always enabled. "
               + "To use JSON inline results with SEA, disable CloudFetch via "
               + "EnableQueryResultDownload=0.");
@@ -1213,6 +1220,13 @@ private String getParameterIgnoreDefault(DatabricksJdbcUrlParams key) {
     return this.parameters.getOrDefault(key.getParamName().toLowerCase(), null);
   }
 
+  /** Returns true if running on AIX or IBM PowerPC architecture. */
+  private static boolean isAixOrPowerPc() {
+    String osName = System.getProperty("os.name", "").toLowerCase();
+    String osArch = System.getProperty("os.arch", "").toLowerCase();
+    return osName.contains("aix") || osArch.contains("ppc");
+  }
+
   /**
    * Resolves a boolean feature flag with client-side priority over server-side.
    *

src/test/java/com/databricks/jdbc/api/impl/DatabricksConnectionContextTest.java

@@ -358,6 +358,21 @@ public void testEnableCloudFetch() throws DatabricksSQLException {
     assertTrue(connectionContext.shouldEnableArrow());
   }
 
+  @Test
+  public void testShouldEnableArrow_defaultIsTrue() throws DatabricksSQLException {
+    // On non-AIX, Arrow is always enabled regardless of EnableArrow setting
+    IDatabricksConnectionContext ctx =
+        DatabricksConnectionContext.parse(TestConstants.VALID_URL_1, properties);
+    assertTrue(ctx.shouldEnableArrow(), "Arrow should be enabled by default");
+  }
+
+  @Test
+  public void testShouldEnableArrow_explicitDisableIgnoredOnNonAix() throws DatabricksSQLException {
+    IDatabricksConnectionContext ctx =
+        DatabricksConnectionContext.parse(TestConstants.VALID_URL_1 + ";EnableArrow=0", properties);
+    assertTrue(ctx.shouldEnableArrow(), "EnableArrow=0 should be ignored on non-AIX");
+  }
+
   @Test
   public void testAllPurposeClusterParsing() throws DatabricksSQLException {
     DatabricksConnectionContext connectionContext =
@@ -947,7 +962,9 @@ public void testClientTypeWithExplicitUseThriftClientDisabled() throws Databrick
   }
 
   @Test
-  public void testClientTypeWhenArrowDisabled() throws DatabricksSQLException {
+  public void testClientTypeWhenArrowDisabled_nonAix_ignoredDefaultsToThrift()
+      throws DatabricksSQLException {
+    // EnableArrow=0 is ignored on non-AIX — but without SEA feature flag, defaults to THRIFT
     String urlWithArrowDisabled =
         "jdbc:databricks://sample-host.cloud.databricks.com:9999/default;AuthMech=3;"
             + "httpPath=/sql/1.0/warehouses/9999999999999999;EnableArrow=0";
@@ -969,7 +986,9 @@ public void testClientTypeWhenCloudFetchDisabled() throws DatabricksSQLException
   }
 
   @Test
-  public void testClientTypeWhenBothArrowAndCloudFetchDisabled() throws DatabricksSQLException {
+  public void testClientTypeWhenBothArrowAndCloudFetchDisabled_nonAix()
+      throws DatabricksSQLException {
+    // EnableArrow=0 ignored on non-AIX; CloudFetch disabled → THRIFT
     String urlWithBothDisabled =
         "jdbc:databricks://sample-host.cloud.databricks.com:9999/default;AuthMech=3;"
             + "httpPath=/sql/1.0/warehouses/9999999999999999;EnableArrow=0;EnableQueryResultDownload=0";

src/test/java/com/databricks/jdbc/integration/fakeservice/tests/SqlExecApiIntegrationTests.java

@@ -14,9 +14,10 @@
 public class SqlExecApiIntegrationTests extends AbstractFakeServiceIntegrationTests {
 
   @Test
-  void testJsonInlineChunkedResults_withoutArrow() throws SQLException {
+  void testChunkedResults_enableArrowDeprecatedIgnored() throws SQLException {
+    // EnableArrow=0 is deprecated and ignored on non-AIX — Arrow is always enabled.
+    // This test verifies the query still succeeds with the deprecated flag set.
     final String table = "samples.tpch.lineitem";
-    // Limit set such that atleast 2 chunks are present for results
     final int maxRows = 64000;
     final String sql = "SELECT * FROM " + table + " limit " + maxRows;