diff --git a/10/Dockerfile b/10/Dockerfile
index 178a62260f..76b3374d47 100644
--- a/10/Dockerfile
+++ b/10/Dockerfile
@@ -48,12 +48,16 @@ RUN set -eux; \
 	localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
 ENV LANG en_US.utf8
 
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
 # install "nss_wrapper" in case we need to fake "/etc/passwd" and "/etc/group" (especially for OpenShift)
 # https://github.com/docker-library/postgres/issues/359
 # https://cwrap.org/nss_wrapper.html
-RUN set -eux; \
-	apt-get update; \
-	apt-get install -y --no-install-recommends libnss-wrapper; \
+		libnss-wrapper \
+# install "xz-utils" for .sql.xz docker-entrypoint-initdb.d files
+		xz-utils \
+	; \
 	rm -rf /var/lib/apt/lists/*
 
 RUN mkdir /docker-entrypoint-initdb.d
diff --git a/10/alpine/docker-entrypoint.sh b/10/alpine/docker-entrypoint.sh
index d0ec89d0cf..78adac6212 100755
--- a/10/alpine/docker-entrypoint.sh
+++ b/10/alpine/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/10/docker-entrypoint.sh b/10/docker-entrypoint.sh
index 8536cf2f21..a9190b4055 100755
--- a/10/docker-entrypoint.sh
+++ b/10/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/11/Dockerfile b/11/Dockerfile
index f1e9df7d15..c237e0ce18 100644
--- a/11/Dockerfile
+++ b/11/Dockerfile
@@ -48,12 +48,16 @@ RUN set -eux; \
 	localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
 ENV LANG en_US.utf8
 
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
 # install "nss_wrapper" in case we need to fake "/etc/passwd" and "/etc/group" (especially for OpenShift)
 # https://github.com/docker-library/postgres/issues/359
 # https://cwrap.org/nss_wrapper.html
-RUN set -eux; \
-	apt-get update; \
-	apt-get install -y --no-install-recommends libnss-wrapper; \
+		libnss-wrapper \
+# install "xz-utils" for .sql.xz docker-entrypoint-initdb.d files
+		xz-utils \
+	; \
 	rm -rf /var/lib/apt/lists/*
 
 RUN mkdir /docker-entrypoint-initdb.d
diff --git a/11/alpine/docker-entrypoint.sh b/11/alpine/docker-entrypoint.sh
index d0ec89d0cf..78adac6212 100755
--- a/11/alpine/docker-entrypoint.sh
+++ b/11/alpine/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/11/docker-entrypoint.sh b/11/docker-entrypoint.sh
index 8536cf2f21..a9190b4055 100755
--- a/11/docker-entrypoint.sh
+++ b/11/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/12/Dockerfile b/12/Dockerfile
index bb24f5ac1c..013d33ab7e 100644
--- a/12/Dockerfile
+++ b/12/Dockerfile
@@ -48,12 +48,16 @@ RUN set -eux; \
 	localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
 ENV LANG en_US.utf8
 
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
 # install "nss_wrapper" in case we need to fake "/etc/passwd" and "/etc/group" (especially for OpenShift)
 # https://github.com/docker-library/postgres/issues/359
 # https://cwrap.org/nss_wrapper.html
-RUN set -eux; \
-	apt-get update; \
-	apt-get install -y --no-install-recommends libnss-wrapper; \
+		libnss-wrapper \
+# install "xz-utils" for .sql.xz docker-entrypoint-initdb.d files
+		xz-utils \
+	; \
 	rm -rf /var/lib/apt/lists/*
 
 RUN mkdir /docker-entrypoint-initdb.d
diff --git a/12/alpine/docker-entrypoint.sh b/12/alpine/docker-entrypoint.sh
index d0ec89d0cf..78adac6212 100755
--- a/12/alpine/docker-entrypoint.sh
+++ b/12/alpine/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/12/docker-entrypoint.sh b/12/docker-entrypoint.sh
index 8536cf2f21..a9190b4055 100755
--- a/12/docker-entrypoint.sh
+++ b/12/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/9.5/Dockerfile b/9.5/Dockerfile
index d17a56b0e2..ec2f6b8117 100644
--- a/9.5/Dockerfile
+++ b/9.5/Dockerfile
@@ -48,12 +48,16 @@ RUN set -eux; \
 	localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
 ENV LANG en_US.utf8
 
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
 # install "nss_wrapper" in case we need to fake "/etc/passwd" and "/etc/group" (especially for OpenShift)
 # https://github.com/docker-library/postgres/issues/359
 # https://cwrap.org/nss_wrapper.html
-RUN set -eux; \
-	apt-get update; \
-	apt-get install -y --no-install-recommends libnss-wrapper; \
+		libnss-wrapper \
+# install "xz-utils" for .sql.xz docker-entrypoint-initdb.d files
+		xz-utils \
+	; \
 	rm -rf /var/lib/apt/lists/*
 
 RUN mkdir /docker-entrypoint-initdb.d
diff --git a/9.5/alpine/docker-entrypoint.sh b/9.5/alpine/docker-entrypoint.sh
index de45d91145..f87b08bdfe 100755
--- a/9.5/alpine/docker-entrypoint.sh
+++ b/9.5/alpine/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/9.5/docker-entrypoint.sh b/9.5/docker-entrypoint.sh
index 2a57e1044d..84eb98d6f1 100755
--- a/9.5/docker-entrypoint.sh
+++ b/9.5/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/9.6/Dockerfile b/9.6/Dockerfile
index 587f982455..fbe2662ea8 100644
--- a/9.6/Dockerfile
+++ b/9.6/Dockerfile
@@ -48,12 +48,16 @@ RUN set -eux; \
 	localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
 ENV LANG en_US.utf8
 
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
 # install "nss_wrapper" in case we need to fake "/etc/passwd" and "/etc/group" (especially for OpenShift)
 # https://github.com/docker-library/postgres/issues/359
 # https://cwrap.org/nss_wrapper.html
-RUN set -eux; \
-	apt-get update; \
-	apt-get install -y --no-install-recommends libnss-wrapper; \
+		libnss-wrapper \
+# install "xz-utils" for .sql.xz docker-entrypoint-initdb.d files
+		xz-utils \
+	; \
 	rm -rf /var/lib/apt/lists/*
 
 RUN mkdir /docker-entrypoint-initdb.d
diff --git a/9.6/alpine/docker-entrypoint.sh b/9.6/alpine/docker-entrypoint.sh
index de45d91145..f87b08bdfe 100755
--- a/9.6/alpine/docker-entrypoint.sh
+++ b/9.6/alpine/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/9.6/docker-entrypoint.sh b/9.6/docker-entrypoint.sh
index 2a57e1044d..84eb98d6f1 100755
--- a/9.6/docker-entrypoint.sh
+++ b/9.6/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo
diff --git a/Dockerfile-debian.template b/Dockerfile-debian.template
index 5fc9727e1b..485137f864 100644
--- a/Dockerfile-debian.template
+++ b/Dockerfile-debian.template
@@ -48,12 +48,16 @@ RUN set -eux; \
 	localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
 ENV LANG en_US.utf8
 
+RUN set -eux; \
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
 # install "nss_wrapper" in case we need to fake "/etc/passwd" and "/etc/group" (especially for OpenShift)
 # https://github.com/docker-library/postgres/issues/359
 # https://cwrap.org/nss_wrapper.html
-RUN set -eux; \
-	apt-get update; \
-	apt-get install -y --no-install-recommends libnss-wrapper; \
+		libnss-wrapper \
+# install "xz-utils" for .sql.xz docker-entrypoint-initdb.d files
+		xz-utils \
+	; \
 	rm -rf /var/lib/apt/lists/*
 
 RUN mkdir /docker-entrypoint-initdb.d
diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index 8536cf2f21..a9190b4055 100755
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -164,6 +164,7 @@ docker_process_init_files() {
 				;;
 			*.sql)    echo "$0: running $f"; docker_process_sql -f "$f"; echo ;;
 			*.sql.gz) echo "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
+			*.sql.xz) echo "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
 			*)        echo "$0: ignoring $f" ;;
 		esac
 		echo