diff --git a/source/conf.ts b/source/conf.ts
index 24e47a7..0389c2b 100644
--- a/source/conf.ts
+++ b/source/conf.ts
@@ -111,10 +111,30 @@ namespace _espe.conf
 				})) (conf_raw["server"] ?? {})
 			),
 			"database": (
-				((node_database) => ({
-					"kind": (node_database["kind"] ?? "sqlite"),
-					"data": node_database["data"],
-				})) (conf_raw["database"] ?? {})
+				((node_database) => {
+					const kind : string = (node_database["kind"] ?? "sqlite");
+					const node_database_data_raw = (node_database["data"] ?? {});
+					switch (kind) {
+						case "sqlite": {
+							return {
+								"kind": kind,
+								"data": {
+									"path": (node_database_data_raw["path"] ?? "data.sqlite"),
+								}
+							};
+						}
+						case "postgresql": {
+							return {
+								"kind": kind,
+								"data": node_database_data_raw,
+							};
+						}
+						default: {
+							throw (new Error("unhandled"));
+							break;
+						}
+					}
+				}) (conf_raw["database"] ?? {})
 			),
 			"email_sending": (
 				((node_email_sending) => ({
diff --git a/source/database.ts b/source/database.ts
new file mode 100644
index 0000000..8ad002e
--- /dev/null
+++ b/source/database.ts
@@ -0,0 +1,251 @@
+namespace _espe.database
+{
+	
+	/**
+	 */
+	enum enum_revision {
+		r0 = 0,
+		r1 = 1,
+	}
+	
+	
+	/**
+	 */
+	const _revision_order : Array<enum_revision> = [
+		enum_revision.r0,
+		enum_revision.r1,
+	];
+	
+	
+	/**
+	 */
+	export function get_implementation(
+	) : lib_plankton.database.type_database
+	{
+		switch (_espe.conf.get().database.kind) {
+			case "sqlite": {
+				return lib_plankton.database.sqlite_database(
+					{
+						"path": _espe.conf.get().database.data["path"],
+						"verbose": false,
+					}
+				);
+				break;
+			}
+			default: {
+				throw (new Error("database implementation not available: " + _espe.conf.get().database.kind));
+			}
+		}
+	}
+	
+	
+	/**
+	 */
+	function get_revision(
+	) : Promise<enum_revision>
+	{
+		return (
+			(
+				get_implementation().query_select(
+					{
+						"source": "meta",
+						"fields": ["revision"],
+					}
+				)
+				.then<int>(
+					(rows) => Promise.resolve<int>(rows[0]["revision"])
+				)
+				.catch<int>(
+					() => Promise.resolve<int>(0)
+				)
+			)
+			.then<enum_revision>(
+				(revision_raw) => Promise.resolve<enum_revision>(revision_raw)
+			)
+		);
+	}
+	
+	
+	/**
+	 */
+	async function advance(
+	) : Promise<boolean>
+	{
+		const implementation : lib_plankton.database.type_database = get_implementation();
+		
+		const revision_current : enum_revision = await get_revision();
+		const index_current : int = _revision_order.indexOf(revision_current);
+		const index_next : (null | int) = (
+			(index_current < (_revision_order.length - 1))
+			? (index_current + 1)
+			: null
+		);
+		const revision_next : (null | enum_revision) = (
+			(index_next !== null)
+			? _revision_order[index_next]
+			: null
+		);
+		if (revision_next !== null) {
+			lib_plankton.log.notice(
+				"database_advancement_necessary",
+				{
+					"revision_current": revision_current,
+					"revision_next": revision_next,
+				}
+			);
+			switch (revision_next) {
+				case enum_revision.r1: {
+					// structure
+					{
+						await implementation.query_create_table(
+							{
+								"name": "meta",
+								"data_fields": [
+									{
+										"name": "revision",
+										"type": lib_plankton.database.enum_type.integer,
+										"nullable": false,
+									},
+								],
+							}
+						);
+						await implementation.query_create_table(
+							{
+								"name": "members",
+								"key_field": {
+									"name": "id"
+								},
+								"data_fields": [
+									{
+										"name": "membership_number",
+										"type": lib_plankton.database.enum_type.string_short,
+										"nullable": false
+									},
+									{
+										"name": "enabled",
+										"type": lib_plankton.database.enum_type.boolean,
+										"nullable": false
+									},
+									{
+										"name": "name_login",
+										"type": lib_plankton.database.enum_type.string_short,
+										"nullable": true
+									},
+									{
+										"name": "password_image",
+										"type": lib_plankton.database.enum_type.string_medium,
+										"nullable": true
+									},
+									{
+										"name": "name_real_value",
+										"type": lib_plankton.database.enum_type.string_medium,
+										"nullable": false
+									},
+									{
+										"name": "name_real_extension",
+										"type": lib_plankton.database.enum_type.string_short,
+										"nullable": true
+									},
+									{
+										"name": "name_display",
+										"type": lib_plankton.database.enum_type.string_medium,
+										"nullable": true
+									},
+									{
+										"name": "salutation",
+										"type": lib_plankton.database.enum_type.string_short,
+										"nullable": true
+									},
+									{
+										"name": "email_address_private_value",
+										"type": lib_plankton.database.enum_type.string_short,
+										"nullable": true
+									},
+									{
+										"name": "email_address_numberbased_use",
+										"type": lib_plankton.database.enum_type.boolean,
+										"nullable": false
+									},
+									{
+										"name": "email_address_namebased_use",
+										"type": lib_plankton.database.enum_type.boolean,
+										"nullable": false
+									},
+									{
+										"name": "email_redirect_to_private",
+										"type": lib_plankton.database.enum_type.boolean,
+										"nullable": false
+									}
+								],
+								"constraints": [
+									{
+										"kind": "unique",
+										"parameters": {
+											"fields": ["membership_number"]
+										}
+									},
+									{
+										"kind": "unique",
+										"parameters": {
+											"fields": ["name_real_value","name_real_extension"]
+										}
+									},
+									{
+										"kind": "unique",
+										"parameters": {
+											"fields": ["name_login"]
+										}
+									}
+								]
+							}
+						);
+					}
+					// data
+					{
+						await implementation.query_insert(
+							{
+								"table_name": "meta",
+								"values": {
+									"revision": revision_next,
+								}
+							}
+						);
+					}
+					return Promise.resolve<boolean>(true);
+					break;
+				}
+				default: {
+					return Promise.reject<boolean>("unhandled advancement step");
+					break;
+				}
+			}
+		}
+		else {
+			lib_plankton.log.notice(
+				"database_up_to_date",
+				{
+					"revision_current": revision_current,
+				}
+			);
+			return Promise.resolve<boolean>(false);
+		}
+	}
+	
+	
+	/**
+	 */
+	export async function advance_all(
+	) : Promise<void>
+	{
+		while (true) {
+			const modified : boolean = await advance();
+			if (modified) {
+				// do nothing
+			}
+			else {
+				break;
+			}
+		}
+	}
+	
+}
diff --git a/source/helpers.ts b/source/helpers.ts
index c547baa..05b2802 100644
--- a/source/helpers.ts
+++ b/source/helpers.ts
@@ -50,24 +50,12 @@ namespace _espe.helpers
 	
 	
 	/**
+	 * @deprecated
 	 */
 	export function database_implementation(
 	) : lib_plankton.database.type_database
 	{
-		switch (_espe.conf.get().database.kind) {
-			case "sqlite": {
-				return lib_plankton.database.sqlite_database(
-					{
-						"path": _espe.conf.get().database.data["path"],
-						"verbose": false,
-					}
-				);
-				break;
-			}
-			default: {
-				throw (new Error("database implementation not available: " + _espe.conf.get().database.kind));
-			}
-		}
+		return _espe.database.get_implementation();
 	}
 	
 	
diff --git a/source/main.ts b/source/main.ts
index 8905028..3653000 100644
--- a/source/main.ts
+++ b/source/main.ts
@@ -125,6 +125,10 @@ async function main(
 				),
 			]
 		);
+		
+		// prepare database
+		await _espe.database.advance_all();
+		
 		switch (args["action"]) {
 			default: {
 				process.stderr.write("invalid action: " + args["action"] + "\n");
diff --git a/tools/makefile b/tools/makefile
index c0b19d1..8cdf9da 100644
--- a/tools/makefile
+++ b/tools/makefile
@@ -27,6 +27,7 @@ node_modules:
 ${dir_temp}/espe-unlinked.js: \
 	${dir_lib}/plankton/plankton.d.ts \
 	${dir_source}/helpers.ts \
+	${dir_source}/database.ts \
 	${dir_source}/service-member.ts \
 	${dir_source}/service-admin.ts \
 	${dir_source}/api/base.ts \