Set replication role to replica to disable FK checks when receiving s…

…ubscription data and TXs when using Postgres on the client.

clients/typescript/src/migrators/query-builder/builder.ts

@@ -27,6 +27,11 @@ export abstract class QueryBuilder {
    */
   abstract readonly getVersion: string
 
+  /**
+   * Disables foreign key checks.
+   */
+  abstract readonly disableForeignKeys: string
+
   /**
    * Returns the given query if the current SQL dialect is PostgreSQL.
    */

clients/typescript/src/migrators/query-builder/pgBuilder.ts

@@ -14,6 +14,9 @@ class PgBuilder extends QueryBuilder {
   readonly paramSign = '$'
   readonly defaultNamespace = 'public'
 
+  /** **Disables** FKs for the duration of the transaction */
+  readonly disableForeignKeys = 'SET LOCAL session_replication_role = replica;'
+
   pgOnly(query: string) {
     return query
   }

clients/typescript/src/migrators/query-builder/sqliteBuilder.ts

@@ -18,6 +18,8 @@ class SqliteBuilder extends QueryBuilder {
     'sqlite_temp_schema',
   ]
 
+  readonly disableForeignKeys = 'PRAGMA foreign_keys = OFF;'
+
   pgOnly(_query: string) {
     return ''
   }

clients/typescript/src/satellite/process.ts

@@ -475,7 +475,17 @@ export class SatelliteProcess implements Satellite {
   ) {
     const namespace = this.builder.defaultNamespace
     const stmts: Statement[] = []
-    stmts.push({ sql: this.builder.deferForeignKeys })
+
+    if (this.builder.dialect === 'Postgres') {
+      // disable FK checks because order of inserts
+      // may not respect referential integrity
+      // and Postgres doesn't let us defer FKs
+      // that were not originally defined as deferrable
+      stmts.push({ sql: this.builder.disableForeignKeys })
+    } else {
+      // Defer FKs on SQLite
+      stmts.push({ sql: this.builder.deferForeignKeys })
+    }
 
     // It's much faster[1] to do less statements to insert the data instead of doing an insert statement for each row
     // so we're going to do just that, but with a caveat: SQLite has a max number of parameters in prepared statements,
@@ -1294,6 +1304,17 @@ export class SatelliteProcess implements Satellite {
     const lsn = transaction.lsn
     let firstDMLChunk = true
 
+    if (this.builder.dialect === 'Postgres') {
+      // Temporarily disable FK checks because order of inserts
+      // may not respect referential integrity
+      // and Postgres doesn't let us defer FKs
+      // that were not originally defined as deferrable
+      stmts.push({ sql: this.builder.disableForeignKeys })
+    } else {
+      // Defer FKs on SQLite
+      stmts.push({ sql: this.builder.deferForeignKeys })
+    }
+
     // update lsn.
     stmts.push(this.updateLsnStmt(lsn))
     stmts.push(this._resetSeenAdditionalDataStmt())

clients/typescript/test/satellite/process.test.ts

@@ -1148,6 +1148,14 @@ export const processTests = (test: TestFn<ContextType>) => {
       builder,
       namespace,
     } = t.context
+    if (builder.dialect === 'Postgres') {
+      // Ignore this unit test for Postgres
+      // because we don't defer FK checks
+      // but completely disable them for incoming transactions
+      t.pass()
+      return
+    }
+
     await runMigrations()
 
     if (builder.dialect === 'SQLite') {
@@ -1269,6 +1277,18 @@ export const processTests = (test: TestFn<ContextType>) => {
       builder,
       namespace,
     } = t.context
+    // since this test disables compensations
+    // by putting the flag on 0
+    // it is expecting a FK violation
+    if (builder.dialect === 'Postgres') {
+      // if we're running Postgres
+      // we are not deferring FK checks
+      // but completely disabling them for incoming transactions
+      // so the FK violation will not occur
+      t.pass()
+      return
+    }
+
     await runMigrations()
 
     if (builder.dialect === 'SQLite') {
@@ -1912,7 +1932,16 @@ export const processTests = (test: TestFn<ContextType>) => {
       authState,
       token,
       namespace,
+      builder,
     } = t.context
+    if (builder.dialect === 'Postgres') {
+      // Ignore this unit test for Postgres
+      // because we don't defer FK checks
+      // but completely disable them for incoming transactions
+      t.pass()
+      return
+    }
+
     await runMigrations()
 
     const tablename = 'child'