✨ Reduce downtime of make refresh by swapping the database

devTools/docker/refresh-grapher-data.sh

@@ -20,20 +20,37 @@ _mysql() {
 }
 
 import_db() {
- cat $1 | gunzip | sed s/.\*DEFINER\=\`.\*// | _mysql $GRAPHER_DB_NAME
+ cat $1 | gunzip | sed s/.\*DEFINER\=\`.\*// | _mysql $2
 }
 
 fillGrapherDb() {
  echo "==> Refreshing grapher database"
- _mysql --database="" -e "DROP DATABASE IF EXISTS $GRAPHER_DB_NAME;CREATE DATABASE $GRAPHER_DB_NAME;ALTER DATABASE $GRAPHER_DB_NAME CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_as_cs;"
 
- if [ -f "${DATA_FOLDER}/owid_metadata.sql.gz" ]; then
- echo "Importing live Grapher metadata database (owid_metadata)"
- import_db $DATA_FOLDER/owid_metadata.sql.gz
- else
- echo "owid_metata.sql.gz missing in ${DATA_FOLDER}. Refresh aborted."
- return 1
- fi
+ TEMP_DB_NAME="${GRAPHER_DB_NAME}_temp"
+
+ # Create a temporary database
+ # _mysql --database="" -e "DROP DATABASE IF EXISTS $TEMP_DB_NAME; CREATE DATABASE $TEMP_DB_NAME; ALTER DATABASE $TEMP_DB_NAME CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_as_cs;"
+
+ # if [ -f "${DATA_FOLDER}/owid_metadata.sql.gz" ]; then
+ # echo "Importing live Grapher metadata database into temporary database (owid_metadata)"
+ # import_db $DATA_FOLDER/owid_metadata.sql.gz $TEMP_DB_NAME
+ # else
+ # echo "owid_metadata.sql.gz missing in ${DATA_FOLDER}. Refresh aborted."
+ # return 1
+ # fi
+
+ # echo "==> Drop owid database and recreate it"
+ # _mysql --database="" -e "DROP DATABASE IF EXISTS $GRAPHER_DB_NAME;CREATE DATABASE $GRAPHER_DB_NAME;ALTER DATABASE $GRAPHER_DB_NAME CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_as_cs;"
+
+ echo "==> Fill new DB with tables"
+ tables=$(_mysql --batch --skip-column-names --database="" -e "SHOW TABLES IN $TEMP_DB_NAME")
+ for table in $tables; do
+ # TODO: doesn't work with views!!! we'd have to recreate them
+ _mysql --database="" -e "RENAME TABLE $TEMP_DB_NAME.$table TO $GRAPHER_DB_NAME.$table;"
+ done
+
+ # Drop the original database and rename the temporary database to the original name
+ # _mysql --database="" -e "DROP DATABASE IF EXISTS $GRAPHER_DB_NAME; RENAME DATABASE $TEMP_DB_NAME TO $GRAPHER_DB_NAME;"
 
  echo "==> ✅ Grapher DB refresh complete"
 }