diff --git a/ci/scripts/e2e-source-test.sh b/ci/scripts/e2e-source-test.sh
index c4b4713af81cc..154d9b7f0509f 100755
--- a/ci/scripts/e2e-source-test.sh
+++ b/ci/scripts/e2e-source-test.sh
@@ -59,6 +59,22 @@ export PGHOST=db PGPORT=5432 PGUSER=postgres PGPASSWORD=postgres PGDATABASE=cdc_
 createdb
 psql < ./e2e_test/source/cdc/postgres_cdc.sql
 
+# to test upper case database
+psql -c "CREATE DATABASE \"UpperDb\";"
+
+export PGHOST=db PGPORT=5432 PGUSER=postgres PGPASSWORD=postgres PGDATABASE=UpperDb
+psql -c "
+CREATE SCHEMA \"UpperSchema\";
+CREATE TABLE \"UpperSchema\".\"Orders\" (
+    id int PRIMARY KEY,
+    name varchar
+);
+INSERT INTO \"UpperSchema\".\"Orders\" VALUES (1, 'happy');
+"
+risedev slt './e2e_test/source/cdc/cdc.upper_case.postgres.slt'
+
+export PGHOST=db PGPORT=5432 PGUSER=postgres PGPASSWORD=postgres PGDATABASE=UpperDb
+
 echo "--- starting risingwave cluster"
 RUST_LOG="debug,risingwave_stream=info,risingwave_batch=info,risingwave_storage=info" \
 risedev ci-start ci-1cn-1fe-with-recovery
diff --git a/e2e_test/source/cdc/cdc.check.slt b/e2e_test/source/cdc/cdc.check.slt
index 446fc7f04b092..3d6ea0e179391 100644
--- a/e2e_test/source/cdc/cdc.check.slt
+++ b/e2e_test/source/cdc/cdc.check.slt
@@ -75,8 +75,3 @@ select * from enum_to_varchar order by id;
 ----
 1 happy
 2 ok
-
-query II
-select * from orders order by id;
-----
-1 happy
diff --git a/e2e_test/source/cdc/cdc.load.slt b/e2e_test/source/cdc/cdc.load.slt
index fb3d1b1d0d0ce..2c372cbd3ffdd 100644
--- a/e2e_test/source/cdc/cdc.load.slt
+++ b/e2e_test/source/cdc/cdc.load.slt
@@ -242,20 +242,3 @@ create table enum_to_varchar (
  table.name = 'enum_table',
  slot.name = 'enum_to_varchar'
 );
-
-
-statement ok
-create table orders (
-  id int,
-  name varchar,
-  PRIMARY KEY (id)
-) with (
- connector = 'postgres-cdc',
- hostname = '${PGHOST:localhost}',
- port = '${PGPORT:5432}',
- username = '${PGUSER:$USER}',
- password = '${PGPASSWORD:}',
- database.name = '${PGDATABASE:postgres}',
- table.name = 'Order',
- slot.name = 'orders'
-);
diff --git a/e2e_test/source/cdc/cdc.share_stream.slt b/e2e_test/source/cdc/cdc.share_stream.slt
index 6091d8b3bc488..3dc26d98c6282 100644
--- a/e2e_test/source/cdc/cdc.share_stream.slt
+++ b/e2e_test/source/cdc/cdc.share_stream.slt
@@ -250,11 +250,6 @@ CREATE TABLE person_new (
     city varchar
 ) FROM pg_source TABLE 'person';
 
-CREATE TABLE orders_shared (
-    id int PRIMARY KEY,
-    name varchar,
-) FROM pg_source TABLE 'Orders';
-
 statement ok
 CREATE TABLE person_new (
     id int,
@@ -496,8 +491,3 @@ select * from enum_to_varchar_shared order by id;
 ----
 1 happy
 2 ok
-
-query II
-select * from orders_shared order by id;
-----
-1 happy
diff --git a/e2e_test/source/cdc/cdc.upper_case.postgres.slt b/e2e_test/source/cdc/cdc.upper_case.postgres.slt
new file mode 100644
index 0000000000000..88b059939ec74
--- /dev/null
+++ b/e2e_test/source/cdc/cdc.upper_case.postgres.slt
@@ -0,0 +1,44 @@
+# For upper case UpperDb
+statement ok
+create source pg_source_upper with (
+ connector = 'postgres-cdc',
+ hostname = '${PGHOST:localhost}',
+ port = '${PGPORT:5432}',
+ username = '${PGUSER:$USER}',
+ password = '${PGPASSWORD:}',
+ database.name = '${PGDATABASE:postgres}',
+ slot.name = 'pg_slot'
+);
+
+statement ok
+CREATE TABLE orders_shared (
+    id int PRIMARY KEY,
+    name varchar,
+) FROM pg_source_upper TABLE 'UpperSchema.Orders';
+
+query II
+select * from orders_shared order by id;
+----
+1 happy
+
+statement ok
+create table orders (
+  id int,
+  name varchar,
+  PRIMARY KEY (id)
+) with (
+ connector = 'postgres-cdc',
+ hostname = '${PGHOST:localhost}',
+ port = '${PGPORT:5432}',
+ username = '${PGUSER:$USER}',
+ password = '${PGPASSWORD:}',
+ database.name = '${PGDATABASE:postgres}',
+ schema.name = 'UpperSchema',
+ table.name = 'Order',
+ slot.name = 'orders'
+);
+
+query II
+select * from orders order by id;
+----
+1 happy
diff --git a/e2e_test/source/cdc/postgres_cdc.sql b/e2e_test/source/cdc/postgres_cdc.sql
index 2831dac183da8..43a120a19d50f 100644
--- a/e2e_test/source/cdc/postgres_cdc.sql
+++ b/e2e_test/source/cdc/postgres_cdc.sql
@@ -106,9 +106,3 @@ CREATE TABLE list_with_null(id int primary key, my_int int[], my_num numeric[],
 INSERT INTO list_with_null VALUES (1, '{1,2,NULL}', '{1.1,inf,NULL}', '{1.1,inf,NULL}', '{1.1,inf,NULL}', '{happy,ok,NULL}', '{bb488f9b-330d-4012-b849-12adeb49e57e,bb488f9b-330d-4012-b849-12adeb49e57f, NULL}', '{\\x00,\\x01,NULL}');
 INSERT INTO list_with_null VALUES (2, '{NULL,3,4}', '{2.2,0,NULL}' , '{2.2,0,NULL}', '{2.2,0,NULL}', '{happy,ok,sad}', '{2de296df-eda7-4202-a81f-1036100ef4f6,2977afbc-0b12-459c-a36f-f623fc9e9840}', '{\\x00,\\x01,\\x02}');
 INSERT INTO list_with_null VALUES (5, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
-
-CREATE TABLE "Orders" (
-    id int PRIMARY KEY,
-    name varchar,
-);
-INSERT INTO "Orders" VALUES (1, 'happy');
\ No newline at end of file
diff --git a/java/connector-node/risingwave-connector-service/src/main/java/com/risingwave/connector/source/common/PostgresValidator.java b/java/connector-node/risingwave-connector-service/src/main/java/com/risingwave/connector/source/common/PostgresValidator.java
index a0f59bbcf15e4..d642273b3d35f 100644
--- a/java/connector-node/risingwave-connector-service/src/main/java/com/risingwave/connector/source/common/PostgresValidator.java
+++ b/java/connector-node/risingwave-connector-service/src/main/java/com/risingwave/connector/source/common/PostgresValidator.java
@@ -180,8 +180,7 @@ private void validateTableSchema() throws SQLException {
         // check primary key
         // reference: https://wiki.postgresql.org/wiki/Retrieve_primary_key_columns
         try (var stmt = jdbcConnection.prepareStatement(ValidatorUtils.getSql("postgres.pk"))) {
-            stmt.setString(1, schemaName);
-            stmt.setString(2, tableName);
+            stmt.setString(1, String.format("\"%s\".\"%s\"", this.schemaName, this.tableName));
             var res = stmt.executeQuery();
             var pkFields = new HashSet<String>();
             while (res.next()) {
diff --git a/java/connector-node/risingwave-connector-service/src/main/resources/validate_sql.properties b/java/connector-node/risingwave-connector-service/src/main/resources/validate_sql.properties
index 61f0868a2dbb8..769c3cb1c8fb0 100644
--- a/java/connector-node/risingwave-connector-service/src/main/resources/validate_sql.properties
+++ b/java/connector-node/risingwave-connector-service/src/main/resources/validate_sql.properties
@@ -6,7 +6,7 @@ mysql.table_schema=SELECT COLUMN_NAME, DATA_TYPE, COLUMN_KEY FROM information_sc
 mysql.grants=SHOW GRANTS FOR CURRENT_USER()
 postgres.wal=show wal_level
 postgres.table=SELECT EXISTS ( SELECT FROM pg_tables WHERE schemaname = ? AND tablename = ?)
-postgres.pk=SELECT a.attname, format_type(a.atttypid, a.atttypmod) AS data_type FROM pg_index i JOIN pg_attribute a ON a.attrelid = i.indrelid AND a.attnum = ANY(i.indkey) JOIN pg_class c ON c.oid = i.indrelid JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = ? AND c.relname = ? AND i.indisprimary
+postgres.pk=SELECT a.attname, format_type(a.atttypid, a.atttypmod) AS data_type FROM pg_index i JOIN pg_attribute a ON a.attrelid = i.indrelid AND a.attnum = ANY(i.indkey) WHERE i.indrelid = ?::regclass AND i.indisprimary
 postgres.table_schema=SELECT column_name, data_type FROM information_schema.columns WHERE table_schema = ? AND table_name = ? ORDER BY ordinal_position
 postgres.slot.check=SELECT slot_name FROM pg_replication_slots WHERE slot_name = ? and database = ?
 postgres.slot_limit.check=SELECT CASE WHEN (SELECT count(*) FROM pg_replication_slots) = (SELECT setting FROM pg_settings WHERE name='max_replication_slots')::int THEN 'true' ELSE 'false' END AS result;