SOFTNETWORK-APP · fupelaqu · Jul 28, 2026 · Jul 27, 2026 · Jul 27, 2026 · Jul 27, 2026
diff --git a/README.md b/README.md
@@ -199,10 +199,12 @@ Download the self-contained fat JAR for your Elasticsearch version:
 
 | Elasticsearch Version | Artifact                               |
 |-----------------------|----------------------------------------|
-| ES 6.x                | `softclient4es6-jdbc-driver-0.2.0.jar` |
-| ES 7.x                | `softclient4es7-jdbc-driver-0.2.0.jar` |
-| ES 8.x                | `softclient4es8-jdbc-driver-0.2.0.jar` |
-| ES 9.x                | `softclient4es9-jdbc-driver-0.2.0.jar` |
+| ES 6.x                | `softclient4es6-jdbc-driver-0.2.1.jar` |
+| ES 7.x                | `softclient4es7-jdbc-driver-0.2.1.jar` |
+| ES 8.x                | `softclient4es8-jdbc-driver-0.2.1.jar` |
+| ES 9.x                | `softclient4es9-jdbc-driver-0.2.1.jar` |
+
+> **Java 11+ recommended** (17+ for ES 9.x): **cross-index JOINs require Java 11+** — the embedded JOIN engine is built on Apache Arrow 18.x, which ships Java-11 bytecode.
 
 ```text
 JDBC URL:    jdbc:elastic://localhost:9200
@@ -217,20 +219,20 @@ Driver class: app.softnetwork.elastic.jdbc.ElasticDriver
 <dependency>
   <groupId>app.softnetwork.elastic</groupId>
   <artifactId>softclient4es8-jdbc-driver</artifactId>
-  <version>0.2.0</version>
+  <version>0.2.1</version>
 </dependency>
 ```
 
 **Gradle:**
 
 ```groovy
-implementation 'app.softnetwork.elastic:softclient4es8-jdbc-driver:0.2.0'
+implementation 'app.softnetwork.elastic:softclient4es8-jdbc-driver:0.2.1'
 ```
 
 **sbt:**
 
 ```scala
-libraryDependencies += "app.softnetwork.elastic" % "softclient4es8-jdbc-driver" % "0.2.0"
+libraryDependencies += "app.softnetwork.elastic" % "softclient4es8-jdbc-driver" % "0.2.1"
 ```
 
 The JDBC driver JARs are Scala-version-independent (no `_2.12` or `_2.13` suffix) and include all required dependencies.
@@ -309,6 +311,8 @@ For programmatic access, add SoftClient4ES to your project.
 | 8.x            | `softclient4es8-java-client` | 2.12, 2.13 | 8+   |
 | 9.x            | `softclient4es9-java-client` | 2.13 only  | 17+  |
 
+> JDK versions above apply to the client libraries themselves. **Cross-index JOINs (via the arrow extensions, the JDBC/ADBC drivers) require Java 11+** — see [Cross-Index JOIN](documentation/sql/joins.md).
+
 ### sbt Setup
 
 ```scala
@@ -320,7 +324,7 @@ libraryDependencies += "app.softnetwork.elastic" %% "softclient4es8-java-client"
 // Add the community extensions for materialized views (optional)
 libraryDependencies += "app.softnetwork.elastic" %% "softclient4es-community-extensions" % "0.2.0"
 // Add the JDBC driver if you want to use it from Scala (optional)
-libraryDependencies += "app.softnetwork.elastic" %% "softclient4es-jdbc-driver" % "0.2.0"
+libraryDependencies += "app.softnetwork.elastic" %% "softclient4es-jdbc-driver" % "0.2.1"
 ```
 
 ```scala

diff --git a/documentation/client/adbc_driver.md b/documentation/client/adbc_driver.md
@@ -23,10 +23,10 @@ Download the self-contained fat JAR for your Elasticsearch version:
 
 | Elasticsearch  | Artifact                                            |
 |----------------|-----------------------------------------------------|
-| ES 6.x         | `softclient4es6-adbc-driver-0.2.0.jar` |
-| ES 7.x         | `softclient4es7-adbc-driver-0.2.0.jar` |
-| ES 8.x         | `softclient4es8-adbc-driver-0.2.0.jar` |
-| ES 9.x         | `softclient4es9-adbc-driver-0.2.0.jar` |
+| ES 6.x         | `softclient4es6-adbc-driver-0.2.1.jar` |
+| ES 7.x         | `softclient4es7-adbc-driver-0.2.1.jar` |
+| ES 8.x         | `softclient4es8-adbc-driver-0.2.1.jar` |
+| ES 9.x         | `softclient4es9-adbc-driver-0.2.1.jar` |
 
 ### Maven / Gradle / sbt
 
@@ -36,20 +36,20 @@ Download the self-contained fat JAR for your Elasticsearch version:
 <dependency>
   <groupId>app.softnetwork.elastic</groupId>
   <artifactId>softclient4es8-adbc-driver</artifactId>
-  <version>0.2.0</version>
+  <version>0.2.1</version>
 </dependency>
 ```
 
 **Gradle:**
 
 ```groovy
-implementation 'app.softnetwork.elastic:softclient4es8-adbc-driver:0.2.0'
+implementation 'app.softnetwork.elastic:softclient4es8-adbc-driver:0.2.1'
 ```
 
 **sbt:**
 
 ```scala
-libraryDependencies += "app.softnetwork.elastic" % "softclient4es8-adbc-driver" % "0.2.0"
+libraryDependencies += "app.softnetwork.elastic" % "softclient4es8-adbc-driver" % "0.2.1"
 ```
 
 ---

diff --git a/documentation/client/arrow_flight_sql.md b/documentation/client/arrow_flight_sql.md
@@ -49,15 +49,15 @@ Available images per ES version:
 ### Fat JAR
 
 ```bash
-java -jar softclient4es8-arrow-flight-sql-0.2.0.jar
+java -jar softclient4es8-arrow-flight-sql-0.2.1.jar
 ```
 
 | Elasticsearch | Artifact |
 |---------------|----------|
-| ES 6.x | `softclient4es6-arrow-flight-sql-0.2.0.jar` |
-| ES 7.x | `softclient4es7-arrow-flight-sql-0.2.0.jar` |
-| ES 8.x | `softclient4es8-arrow-flight-sql-0.2.0.jar` |
-| ES 9.x | `softclient4es9-arrow-flight-sql-0.2.0.jar` |
+| ES 6.x | `softclient4es6-arrow-flight-sql-0.2.1.jar` |
+| ES 7.x | `softclient4es7-arrow-flight-sql-0.2.1.jar` |
+| ES 8.x | `softclient4es8-arrow-flight-sql-0.2.1.jar` |
+| ES 9.x | `softclient4es9-arrow-flight-sql-0.2.1.jar` |
 
 ---
 

diff --git a/documentation/client/download_analytics.md b/documentation/client/download_analytics.md
@@ -15,7 +15,7 @@ beacon to a public endpoint with exactly these fields:
 |---------------|----------|-----------------------------------------------|
 | `source`      | `portal` | Where the count came from (the docs button)   |
 | `driver`      | `jdbc`   | Which driver family (`jdbc` or `adbc`)        |
-| `version`     | `0.2.0`  | The published artifact version                |
+| `version`     | `0.2.1`  | The published artifact version                |
 | `count_delta` | `1`      | One download                                  |
 
 A timestamp is added on the server. That is the **entire** record.

diff --git a/documentation/client/jdbc.md b/documentation/client/jdbc.md
@@ -20,10 +20,10 @@ Download the self-contained fat JAR for your Elasticsearch version. The JARs are
 
 | Elasticsearch | Artifact |
 |---------------|----------|
-| ES 6.x | `softclient4es6-jdbc-driver-0.2.0.jar` |
-| ES 7.x | `softclient4es7-jdbc-driver-0.2.0.jar` |
-| ES 8.x | `softclient4es8-jdbc-driver-0.2.0.jar` |
-| ES 9.x | `softclient4es9-jdbc-driver-0.2.0.jar` |
+| ES 6.x | `softclient4es6-jdbc-driver-0.2.1.jar` |
+| ES 7.x | `softclient4es7-jdbc-driver-0.2.1.jar` |
+| ES 8.x | `softclient4es8-jdbc-driver-0.2.1.jar` |
+| ES 9.x | `softclient4es9-jdbc-driver-0.2.1.jar` |
 
 ### Build Tool Integration
 
@@ -33,20 +33,20 @@ Download the self-contained fat JAR for your Elasticsearch version. The JARs are
 <dependency>
   <groupId>app.softnetwork.elastic</groupId>
   <artifactId>softclient4es8-jdbc-driver</artifactId>
-  <version>0.2.0</version>
+  <version>0.2.1</version>
 </dependency>
 ```
 
 **Gradle:**
 
 ```groovy
-implementation 'app.softnetwork.elastic:softclient4es8-jdbc-driver:0.2.0'
+implementation 'app.softnetwork.elastic:softclient4es8-jdbc-driver:0.2.1'
 ```
 
 **sbt:**
 
 ```scala
-libraryDependencies += "app.softnetwork.elastic" % "softclient4es8-jdbc-driver" % "0.2.0"
+libraryDependencies += "app.softnetwork.elastic" % "softclient4es8-jdbc-driver" % "0.2.1"
 ```
 
 ---

diff --git a/documentation/client/repl.md b/documentation/client/repl.md
@@ -42,11 +42,15 @@ It provides:
 
 | Elasticsearch Version | Minimum Java Version |
 |-----------------------|----------------------|
-| ES 6                  | Java 8+              |
-| ES 7                  | Java 8+              |
-| ES 8                  | Java 8+              |
+| ES 6                  | Java 11+             |
+| ES 7                  | Java 11+             |
+| ES 8                  | Java 11+             |
 | ES 9                  | Java 17+             |
 
+> The 0.20+ REPL requires **Java 11+** on every ES version: the CLI bundles logback
+> 1.5.x and the JOIN engine is built on Apache Arrow 18.x — both ship Java-11
+> bytecode. See [Extensions](#extensions-cross-index-joins-materialized-views).
+
 ### Network Requirements
 
 - Network access to JFrog repository (`softnetwork.jfrog.io`)
@@ -60,27 +64,27 @@ It provides:
 #### Linux / macOS
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/SOFTNETWORK-APP/softclient4es/main/install.sh | bash
+curl -fsSL https://raw.githubusercontent.com/SOFTNETWORK-APP/SoftClient4ES/main/install.sh | bash
 ```
 
 Or download and run manually:
 
 ```bash
-curl -O https://raw.githubusercontent.com/SOFTNETWORK-APP/softclient4es/main/install.sh
+curl -O https://raw.githubusercontent.com/SOFTNETWORK-APP/SoftClient4ES/main/install.sh
 chmod +x install.sh
 ./install.sh
 ```
 
 #### Windows (PowerShell)
 
 ```powershell
-irm https://raw.githubusercontent.com/SOFTNETWORK-APP/softclient4es/main/install.ps1 | iex
+irm https://raw.githubusercontent.com/SOFTNETWORK-APP/SoftClient4ES/main/install.ps1 | iex
 ```
 
 Or download and run manually:
 
 ```powershell
-Invoke-WebRequest -Uri https://raw.githubusercontent.com/SOFTNETWORK-APP/softclient4es/main/install.ps1 -OutFile install.ps1
+Invoke-WebRequest -Uri https://raw.githubusercontent.com/SOFTNETWORK-APP/SoftClient4ES/main/install.ps1 -OutFile install.ps1
 .\install.ps1
 ```
 
@@ -193,7 +197,8 @@ softclient4es/
 │   ├── application.conf        # Application configuration
 │   └── logback.xml             # Logging configuration
 ├── lib/
-│   └── softclient4es8-cli_2.13-x.y.z-assembly.jar
+│   ├── softclient4es8-cli_2.13-x.y.z-assembly.jar
+│   └── ...                     # extension jars + their dependencies (see Extensions)
 ├── logs/                       # Log files directory
 │   └── softclient4es.log       # (created at runtime)
 ├── LICENSE
@@ -202,6 +207,51 @@ softclient4es/
 └── uninstall.sh
 ```
 
+### Extensions (cross-index JOINs, materialized views)
+
+Cross-index `JOIN`s and materialized views are delivered as **extensions** — separate
+jars discovered on the classpath through the `ExtensionSpi` ServiceLoader mechanism:
+
+- `softclient4es-arrow-extensions` — the cross-index JOIN engine (**required for
+  `SELECT … JOIN` across indices** — the same engine the JDBC driver embeds)
+- `softclient4es-community-extensions` — materialized views and quota enforcement
+
+**The installer sets these up by default** — no manual step:
+
+- **community extensions**: always installed — any engine version (matching 0.1.x line
+  for engines < 0.20)
+- **arrow extensions**: installed for engines ≥ 0.20 (requires Java 11+, like the
+  0.20+ CLI itself — Apache Arrow 18.x ships Java-11 bytecode)
+
+Each extension is resolved **with its full dependency closure** (Apache Arrow, DuckDB,
+…; ~250 jars) via a bundled [coursier](https://get-coursier.io) resolver into `lib/`.
+The launcher runs the REPL with `java -cp "<assembly>:lib/*"`, so every jar in `lib/`
+is visible.
+
+To skip them:
+
+```bash
+./install.sh --no-extensions        # minimal install — JOINs and MVs unavailable
+```
+
+**Manual installation on an existing install** (or air-gapped preparation):
+
+```bash
+# Resolve each extension with all its dependencies into lib/
+cs fetch --repository https://softnetwork.jfrog.io/artifactory/releases \
+  "app.softnetwork.elastic:softclient4es-arrow-extensions_2.13:<version>" \
+  "app.softnetwork.elastic:softclient4es-community-extensions_2.13:<version>" \
+  | xargs -I{} cp {} ~/softclient4es/lib/
+```
+
+> ⚠️ **Copying only the two extension jars into `lib/` is NOT enough** — they are thin
+> jars whose engine (Arrow memory, DuckDB, Flight) arrives transitively. Always resolve
+> the full dependency closure as above. Installations made with an installer older than
+> the 0.20 line launched the REPL with `java -jar`, which ignores `lib/` entirely —
+> re-run the installer to get the classpath-based launcher.
+
+The launcher adds the required Arrow `--add-opens` flags automatically on Java 9+.
+
 ### Add to PATH
 
 #### Linux / macOS

diff --git a/documentation/sql/joins.md b/documentation/sql/joins.md
@@ -7,6 +7,8 @@ Elasticsearch has no native cross-index JOIN — and a stock JDBC driver on top
 1. **Query-time cross-index JOIN** — `INNER` / `LEFT` / `RIGHT` / `FULL OUTER` joins across indices (and across clusters), at query time, on **every** surface: the REPL, the JDBC driver, the ADBC driver, the Arrow Flight SQL sidecar, and Federation. The drivers are the **free delivery channel**; the JOIN *depth* is metered.
 2. **Persisted [Materialized Views](materialized_views.md)** — the other superpower: denormalize cross-index data once into a queryable view. (That has its own page; this page is about query-time JOINs.)
 
+> **Runtime requirement — Java 11+.** The JOIN engine is built on Apache Arrow 18.x, which ships Java-11 bytecode, and the 0.20+ REPL/driver line also bundles logback 1.5.x (Java-11 as well). Every JVM-side surface (the REPL, the JDBC/ADBC drivers) requires **Java 11 or newer** at runtime (17+ for ES 9); the Flight SQL and Federation Docker images bundle their own Java 17. In the REPL, the installer sets the extensions up for you (see the [REPL Extensions section](../client/repl.md#extensions-cross-index-joins-materialized-views)).
+
 ## The JOIN ladder
 
 Three meters gate how far a JOIN can reach. Think of them as rungs:

diff --git a/install.ps1 b/install.ps1
@@ -50,7 +50,7 @@ Examples:
   .\install.ps1
   .\install.ps1 -ListVersions -EsVersion 8
   .\install.ps1 -Target "C:\tools\softclient4es" -EsVersion 8 -Version 1.0.0
-  .\install.ps1 -EsVersion 7 -Version 0.2.0
+  .\install.ps1 -EsVersion 7 -Version 0.20.0
 
 "@
     exit 0