[improvement](build) Remove Hive JuiceFS hard dependency on MySQL

### What problem does this PR solve?

Issue Number: None

Related PR: None

Problem Summary: Switch Hive JuiceFS metadata default to Hive metastore PostgreSQL, add PostgreSQL metadata database bootstrap in startup script, and remove logic that auto-enables mysql when starting hive2/hive3.

### Release note

None

### Check List (For Author)

- Test: Manual test

    - Regression test / Unit Test / Manual test / No need to test (with reason)

    - Ran: sudo bash docker/thirdparties/run-thirdparties-docker.sh -c hive3 --hive-mode refresh --hive-modules preinstalled_hql

- Behavior changed: Yes (hive startup no longer auto-requires mysql for JuiceFS metadata by default)

- Does this need documentation: No

Author: suxiaogang223

docker/thirdparties/docker-compose/hive/hive-2x_settings.env

@@ -28,5 +28,5 @@ export PG_PORT=5432 # should be same as hive2PgPort in regression-conf.groovy
 # JuiceFS metadata endpoint for property `juicefs.cluster.meta`.
 # CI can override this env, e.g. to point at the docker-published mysql_57 port:
 #   export JFS_CLUSTER_META="mysql://user:pwd@(127.0.0.1:3316)/juicefs_meta"
-# default to mysql_57 (3316) because external pipeline always starts mysql, but not redis.
-export JFS_CLUSTER_META="${JFS_CLUSTER_META:-mysql://root:123456@(127.0.0.1:3316)/juicefs_meta}"
+# default to hive metastore postgresql to avoid external mysql dependency.
+export JFS_CLUSTER_META="${JFS_CLUSTER_META:-postgres://postgres@127.0.0.1:${PG_PORT}/juicefs_meta?sslmode=disable}"

docker/thirdparties/docker-compose/hive/hive-3x_settings.env

@@ -26,9 +26,10 @@ export HS_PORT=13000 # should be same as hive3ServerPort in regression-conf.groo
 export PG_PORT=5732 # should be same as hive3PgPort in regression-conf.groovy
 
 # JuiceFS metadata endpoint for property `juicefs.cluster.meta`.
-# CI can override this env, e.g. to point at the docker-published mysql_57 port:
+# Default to hive metastore postgresql to avoid external mysql dependency.
+# CI can still override this env, e.g.:
 #   export JFS_CLUSTER_META="mysql://user:pwd@(127.0.0.1:3316)/juicefs_meta"
-export JFS_CLUSTER_META="${JFS_CLUSTER_META:-mysql://root:123456@(127.0.0.1:3316)/juicefs_meta}"
+export JFS_CLUSTER_META="${JFS_CLUSTER_META:-postgres://postgres@127.0.0.1:${PG_PORT}/juicefs_meta?sslmode=disable}"
 
 # prepare for paimon hms test,control load paimon hms data or not
 export enablePaimonHms="false"

docker/thirdparties/run-thirdparties-docker.sh

@@ -260,25 +260,6 @@ if [[ "${RUN_HIVE3}" -eq 1 ]] && [[ -z "${HIVE3_BOOTSTRAP_GROUPS+x}" ]]; then
     export HIVE3_BOOTSTRAP_GROUPS="common,hive3_only"
 fi
 
-hive_requires_mysql_component() {
-    local hive_version="$1"
-    local jfs_meta=""
-    local settings_env="${ROOT}/docker-compose/hive/hive-${hive_version#hive}x_settings.env"
-
-    # shellcheck disable=SC1090
-    . "${settings_env}"
-    jfs_meta="${JFS_CLUSTER_META:-}"
-    [[ "${jfs_meta}" == mysql://* ]] || return 1
-    [[ "${jfs_meta}" == *"@(127.0.0.1:3316)/"* || "${jfs_meta}" == *"@(localhost:3316)/"* ]]
-}
-
-if [[ "${RUN_HIVE2}" -eq 1 ]] && hive_requires_mysql_component "hive2"; then
-    RUN_MYSQL=1
-fi
-if [[ "${RUN_HIVE3}" -eq 1 ]] && hive_requires_mysql_component "hive3"; then
-    RUN_MYSQL=1
-fi
-
 reserve_ports() {
     if [[ "${NEED_RESERVE_PORTS}" -eq 0 ]]; then
         return
@@ -377,25 +358,68 @@ ensure_juicefs_meta_database() {
     local jfs_meta="$1"
     local meta_db
     local mysql_container
+    local pg_container
+    local -a pg_candidates
 
-    if [[ "${jfs_meta}" != *"@(127.0.0.1:3316)/"* && "${jfs_meta}" != *"@(localhost:3316)/"* ]]; then
+    meta_db="${jfs_meta##*/}"
+    meta_db="${meta_db%%\?*}"
+    if [[ ! "${meta_db}" =~ ^[A-Za-z0-9_]+$ ]]; then
+        echo "WARN: skip JuiceFS metadata database creation for unsafe database name '${meta_db}'." >&2
         return 0
     fi
 
-    meta_db="${jfs_meta##*/}"
-    meta_db="${meta_db%%\?*}"
+    if [[ "${jfs_meta}" == mysql://* ]]; then
+        if [[ "${jfs_meta}" != *"@(127.0.0.1:3316)/"* && "${jfs_meta}" != *"@(localhost:3316)/"* ]]; then
+            return 0
+        fi
 
-    mysql_container=$(sudo docker ps --format '{{.Names}}' | grep -E "(^|-)${CONTAINER_UID}mysql_57(-[0-9]+)?$" | head -n 1 || true)
-    if [[ -n "${mysql_container}" ]]; then
-        if sudo docker exec "${mysql_container}" \
-            mysql -uroot -p123456 -e "CREATE DATABASE IF NOT EXISTS \`${meta_db}\`;" >/dev/null 2>&1; then
+        mysql_container=$(sudo docker ps --format '{{.Names}}' | grep -E "(^|-)${CONTAINER_UID}mysql_57(-[0-9]+)?$" | head -n 1 || true)
+        if [[ -n "${mysql_container}" ]]; then
+            if sudo docker exec "${mysql_container}" \
+                mysql -uroot -p123456 -e "CREATE DATABASE IF NOT EXISTS \`${meta_db}\`;" >/dev/null 2>&1; then
+                return 0
+            fi
+            echo "WARN: docker mysql ${mysql_container} is unavailable for JuiceFS metadata init." >&2
             return 0
         fi
-        echo "WARN: docker mysql ${mysql_container} is unavailable for JuiceFS metadata init." >&2
+
+        echo "WARN: docker mysql_57 is not running; skip eager JuiceFS metadata database creation for ${meta_db}." >&2
+        return 0
+    fi
+
+    if [[ "${jfs_meta}" == postgres://* || "${jfs_meta}" == postgresql://* ]]; then
+        if [[ "${jfs_meta}" != *"@127.0.0.1:"* && "${jfs_meta}" != *"@localhost:"* ]]; then
+            return 0
+        fi
+
+        pg_candidates=(
+            "${CONTAINER_UID}hive3-metastore-postgresql"
+            "${CONTAINER_UID}hive2-metastore-postgresql"
+        )
+
+        for pg_container in "${pg_candidates[@]}"; do
+            if ! sudo docker ps --format '{{.Names}}' | grep -Fxq "${pg_container}"; then
+                continue
+            fi
+
+            if sudo docker exec "${pg_container}" \
+                psql -U postgres -d postgres -tAc "SELECT 1 FROM pg_database WHERE datname='${meta_db}'" | grep -q '^1$'; then
+                return 0
+            fi
+
+            if sudo docker exec "${pg_container}" \
+                psql -U postgres -d postgres -c "CREATE DATABASE \"${meta_db}\";" >/dev/null 2>&1; then
+                return 0
+            fi
+
+            echo "WARN: docker postgres ${pg_container} is unavailable for JuiceFS metadata init." >&2
+            return 0
+        done
+
+        echo "WARN: hive metastore postgresql is not running; skip eager JuiceFS metadata database creation for ${meta_db}." >&2
         return 0
     fi
 
-    echo "WARN: docker mysql_57 is not running; skip eager JuiceFS metadata database creation for ${meta_db}." >&2
     return 0
 }
 
@@ -433,7 +457,10 @@ ensure_juicefs_hadoop_jar_for_hive() {
 prepare_juicefs_meta_for_hive() {
     local jfs_meta="$1"
     local jfs_cluster_name="${2:-cluster}"
-    if [[ -z "${jfs_meta}" || "${jfs_meta}" != mysql://* ]]; then
+    if [[ -z "${jfs_meta}" ]]; then
+        return 0
+    fi
+    if [[ "${jfs_meta}" != mysql://* && "${jfs_meta}" != postgres://* && "${jfs_meta}" != postgresql://* ]]; then
         return 0
     fi
     if [[ "${JFS_META_FORMATTED}" -eq 1 ]]; then
@@ -444,7 +471,7 @@ prepare_juicefs_meta_for_hive() {
     sudo mkdir -p "${bucket_dir}"
     sudo chmod 777 "${bucket_dir}"
 
-    # For the default docker mysql_57 metadata DSN, ensure metadata database exists.
+    # For local docker metadata DSNs (mysql/postgresql), ensure metadata database exists.
     ensure_juicefs_meta_database "${jfs_meta}"
 
     if run_juicefs_cli status "${jfs_meta}" >/dev/null 2>&1; then