diff --git a/src/common/customizations/mysql.js b/src/common/customizations/mysql.js
index 7496eb62..ff471b34 100644
--- a/src/common/customizations/mysql.js
+++ b/src/common/customizations/mysql.js
@@ -62,5 +62,6 @@ module.exports = {
    functionDeterministic: true,
    functionDataAccess: true,
    functionSql: 'BEGIN\r\n\r\nEND',
-   parametersLength: true
+   parametersLength: true,
+   readOnlyMode: true
 };
diff --git a/src/common/customizations/postgresql.js b/src/common/customizations/postgresql.js
index 078ce79e..ff67b892 100644
--- a/src/common/customizations/postgresql.js
+++ b/src/common/customizations/postgresql.js
@@ -54,5 +54,6 @@ module.exports = {
    triggerTableInName: true,
    triggerOnlyRename: false,
    triggerEnableDisable: true,
-   languages: ['sql', 'plpgsql', 'c', 'internal']
+   languages: ['sql', 'plpgsql', 'c', 'internal'],
+   readOnlyMode: true
 };
diff --git a/src/main/libs/clients/MySQLClient.js b/src/main/libs/clients/MySQLClient.js
index 7d10ce3e..11714301 100644
--- a/src/main/libs/clients/MySQLClient.js
+++ b/src/main/libs/clients/MySQLClient.js
@@ -133,8 +133,12 @@ export class MySQLClient extends AntaresCore {
          }
       }
 
-      if (!this._poolSize)
+      if (!this._poolSize) {
          this._connection = await mysql.createConnection(dbConfig);
+
+         if (this._params.readonly)
+            await this.raw('SET SESSION TRANSACTION READ ONLY');
+      }
       else {
          this._connection = mysql.createPool({
             ...dbConfig,
@@ -146,6 +150,12 @@ export class MySQLClient extends AntaresCore {
                   return next();
             }
          });
+
+         if (this._params.readonly) {
+            this._connection.on('connection', connection => {
+               connection.query('SET SESSION TRANSACTION READ ONLY');
+            });
+         }
       }
    }
 
diff --git a/src/main/libs/clients/PostgreSQLClient.js b/src/main/libs/clients/PostgreSQLClient.js
index 6a68948f..7c2e65fc 100644
--- a/src/main/libs/clients/PostgreSQLClient.js
+++ b/src/main/libs/clients/PostgreSQLClient.js
@@ -105,10 +105,19 @@ export class PostgreSQLClient extends AntaresCore {
          const client = new Client(dbConfig);
          await client.connect();
          this._connection = client;
+
+         if (this._params.readonly)
+            await this.raw('SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY');
       }
       else {
          const pool = new Pool({ ...dbConfig, max: this._poolSize });
          this._connection = pool;
+
+         if (this._params.readonly) {
+            this._connection.on('connect', connection => {
+               connection.query('SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY');
+            });
+         }
       }
    }