Remove Sequence batching in favour of always using JPA increment 50

src/main/java/io/ebean/config/PlatformConfig.java

@@ -34,11 +34,6 @@ public class PlatformConfig {
    */
   private String databaseBooleanFalse;
 
-  /**
-   * For DB's using sequences this is the number of sequence values prefetched.
-   */
-  private int databaseSequenceBatchSize = 20;
-
   /**
    * Set for DB's that support both Sequence and Identity (and the default choice is not desired).
    */
@@ -79,7 +74,6 @@ public PlatformConfig() {
   public PlatformConfig(PlatformConfig platformConfig) {
     this.databaseBooleanFalse = platformConfig.databaseBooleanFalse;
     this.databaseBooleanTrue = platformConfig.databaseBooleanTrue;
-    this.databaseSequenceBatchSize = platformConfig.databaseSequenceBatchSize;
     this.idType = platformConfig.idType;
     this.geometrySRID = platformConfig.geometrySRID;
     this.dbUuid = platformConfig.dbUuid;
@@ -173,20 +167,6 @@ public void setDatabaseBooleanFalse(String databaseBooleanFalse) {
     this.databaseBooleanFalse = databaseBooleanFalse;
   }
 
-  /**
-   * Return the number of DB sequence values that should be preallocated.
-   */
-  public int getDatabaseSequenceBatchSize() {
-    return databaseSequenceBatchSize;
-  }
-
-  /**
-   * Set the number of DB sequence values that should be preallocated.
-   */
-  public void setDatabaseSequenceBatchSize(int databaseSequenceBatchSize) {
-    this.databaseSequenceBatchSize = databaseSequenceBatchSize;
-  }
-
   /**
    * Return the Geometry SRID.
    */
@@ -294,7 +274,6 @@ public List<CustomDbTypeMapping> getCustomTypeMappings() {
   public void loadSettings(PropertiesWrapper p) {
 
     idType = p.getEnum(IdType.class, "idType", idType);
-    databaseSequenceBatchSize = p.getInt("databaseSequenceBatchSize", databaseSequenceBatchSize);
     databaseBooleanTrue = p.get("databaseBooleanTrue", databaseBooleanTrue);
     databaseBooleanFalse = p.get("databaseBooleanFalse", databaseBooleanFalse);
     databaseInetAddressVarchar = p.getBoolean("databaseInetAddressVarchar", databaseInetAddressVarchar);

src/main/java/io/ebean/config/ServerConfig.java

@@ -1050,18 +1050,6 @@ public void setLazyLoadBatchSize(int lazyLoadBatchSize) {
     this.lazyLoadBatchSize = lazyLoadBatchSize;
   }
 
-  /**
-   * Set the number of sequences to fetch/preallocate when using DB sequences.
-   * <p>
-   * This is a performance optimisation to reduce the number times Ebean
-   * requests a sequence to be used as an Id for a bean (aka reduce network
-   * chatter).
-   * </p>
-   */
-  public void setDatabaseSequenceBatchSize(int databaseSequenceBatchSize) {
-    platformConfig.setDatabaseSequenceBatchSize(databaseSequenceBatchSize);
-  }
-
   /**
    * Return the default JDBC fetchSize hint for findList queries.
    */
@@ -1828,32 +1816,6 @@ public void setDatabaseBooleanFalse(String databaseFalse) {
     this.platformConfig.setDatabaseBooleanFalse(databaseFalse);
   }
 
-  /**
-   * Return the number of DB sequence values that should be preallocated.
-   */
-  public int getDatabaseSequenceBatchSize() {
-    return platformConfig.getDatabaseSequenceBatchSize();
-  }
-
-  /**
-   * Set the number of DB sequence values that should be preallocated and cached
-   * by Ebean.
-   * <p>
-   * This is only used for DB's that use sequences and is a performance
-   * optimisation. This reduces the number of times Ebean needs to get a
-   * sequence value from the Database reducing network chatter.
-   * </p>
-   * <p>
-   * By default this value is 10 so when we need another Id (and don't have one
-   * in our cache) Ebean will fetch 10 id's from the database. Note that when
-   * the cache drops to have full (which is 5 by default) Ebean will fetch
-   * another batch of Id's in a background thread.
-   * </p>
-   */
-  public void setDatabaseSequenceBatch(int databaseSequenceBatchSize) {
-    this.platformConfig.setDatabaseSequenceBatchSize(databaseSequenceBatchSize);
-  }
-
   /**
    * Return the database platform name (can be null).
    * <p>

src/main/java/io/ebean/config/dbplatform/DatabasePlatform.java

@@ -110,10 +110,6 @@ public enum OnQueryOnly {
    */
   protected DbIdentity dbIdentity = new DbIdentity();
 
-  protected boolean sequenceBatchMode = true;
-
-  protected int sequenceBatchSize = 20;
-
   /**
    * The history support for this database platform.
    */
@@ -235,7 +231,6 @@ public PersistenceException translate(String message, SQLException e) {
    * Configure the platform given the server configuration.
    */
   public void configure(PlatformConfig config) {
-    this.sequenceBatchSize = config.getDatabaseSequenceBatchSize();
     this.caseSensitiveCollation = config.isCaseSensitiveCollation();
     configureIdType(config.getIdType());
     configure(config, config.isAllQuotedIdentifiers());
@@ -298,20 +293,6 @@ public String getName() {
     return platform.name().toLowerCase();
   }
 
-  /**
-   * Return true if we are using Sequence batch mode rather than STEP.
-   */
-  public boolean isSequenceBatchMode() {
-    return sequenceBatchMode;
-  }
-
-  /**
-   * Set to false to not use sequence batch mode but instead STEP mode.
-   */
-  public void setSequenceBatchMode(boolean sequenceBatchMode) {
-    this.sequenceBatchMode = sequenceBatchMode;
-  }
-
   /**
    * Return true if this database platform supports native ILIKE expression.
    */
@@ -381,13 +362,13 @@ public boolean useExtraTransactionOnIterateSecondaryQueries() {
   /**
    * Return a DB Sequence based IdGenerator.
    *
-   * @param be       the BackgroundExecutor that can be used to load the sequence if
-   *                 desired
-   * @param ds       the DataSource
-   * @param stepSize the sequence allocation size as defined by mapping (defaults to 50)
-   * @param seqName  the name of the sequence
+   * @param be        the BackgroundExecutor that can be used to load the sequence if
+   *                  desired
+   * @param ds        the DataSource
+   * @param increment the sequence allocation size as defined by mapping (defaults to 50)
+   * @param seqName   the name of the sequence
    */
-  public PlatformIdGenerator createSequenceIdGenerator(BackgroundExecutor be, DataSource ds, int stepSize, String seqName) {
+  public PlatformIdGenerator createSequenceIdGenerator(BackgroundExecutor be, DataSource ds, int increment, String seqName) {
     return null;
   }
 

src/main/java/io/ebean/config/dbplatform/SequenceIdGenerator.java

@@ -59,7 +59,7 @@ protected SequenceIdGenerator(BackgroundExecutor be, DataSource ds, String seqNa
     this.allocationSize = allocationSize;
   }
 
-  public abstract String getSql(int batchSize);
+  public abstract String getSql();
 
   /**
    * Returns the sequence name.
@@ -102,7 +102,7 @@ public Object nextId(Transaction t) {
       if (size > 0) {
         maybeLoadMoreInBackground(size);
       } else {
-        loadMore(allocationSize);
+        loadMore();
       }
       return idList.pollFirst();
     }
@@ -116,8 +116,8 @@ private void maybeLoadMoreInBackground(int currentSize) {
     }
   }
 
-  private void loadMore(int requestSize) {
-    List<Long> newIds = getMoreIds(requestSize);
+  private void loadMore() {
+    List<Long> newIds = getMoreIds();
     synchronized (monitor) {
       idList.addAll(newIds);
     }
@@ -139,7 +139,7 @@ protected void loadInBackground(final int requestSize) {
       currentlyBackgroundLoading = true;
 
       backgroundExecutor.execute(() -> {
-        loadMore(requestSize);
+        loadMore();
         synchronized (backgroundLoadMonitor) {
           currentlyBackgroundLoading = false;
         }
@@ -150,14 +150,14 @@ protected void loadInBackground(final int requestSize) {
   /**
    * Read the resultSet returning the list of Id values.
    */
-  protected abstract List<Long> readIds(ResultSet resultSet, int loadSize) throws SQLException;
+  protected abstract List<Long> readIds(ResultSet resultSet) throws SQLException;
 
   /**
    * Get more Id's by executing a query and reading the Id's returned.
    */
-  protected List<Long> getMoreIds(int requestSize) {
+  protected List<Long> getMoreIds() {
 
-    String sql = getSql(requestSize);
+    String sql = getSql();
 
     Connection connection = null;
     PreparedStatement statement = null;
@@ -168,7 +168,7 @@ protected List<Long> getMoreIds(int requestSize) {
       statement = connection.prepareStatement(sql);
       resultSet = statement.executeQuery();
 
-      List<Long> newIds = readIds(resultSet, requestSize);
+      List<Long> newIds = readIds(resultSet);
       if (logger.isTraceEnabled()) {
         logger.trace("seq:{} loaded:{} sql:{}", seqName, newIds.size(), sql);
       }

src/main/java/io/ebean/config/dbplatform/SequenceStepIdGenerator.java

@@ -13,19 +13,25 @@
  */
 public abstract class SequenceStepIdGenerator extends SequenceIdGenerator {
 
+  private final String nextSql;
   /**
    * Construct with stepSize (typically 50).
    */
-  protected SequenceStepIdGenerator(BackgroundExecutor be, DataSource ds, String seqName, int stepSize) {
+  protected SequenceStepIdGenerator(BackgroundExecutor be, DataSource ds, String seqName, int stepSize, String nextSql) {
     super(be, ds, seqName, stepSize);
+    this.nextSql = nextSql;
+  }
+
+  @Override
+  public String getSql() {
+    return nextSql;
   }
 
   /**
    * Add the next set of Ids as the next value plus all the following numbers up to the step size.
    */
   @Override
-  protected List<Long> readIds(ResultSet resultSet, int ignoreRequestSize) throws SQLException {
-
+  protected List<Long> readIds(ResultSet resultSet) throws SQLException {
     List<Long> newIds = new ArrayList<>(allocationSize);
     if (resultSet.next()) {
       long start = resultSet.getLong(1);

src/main/java/io/ebean/config/dbplatform/db2/DB2Platform.java

@@ -52,9 +52,8 @@ public DB2Platform() {
    * sequence values.
    */
   @Override
-  public PlatformIdGenerator createSequenceIdGenerator(BackgroundExecutor be, DataSource ds, int stepSize, String seqName) {
-
-    return new DB2SequenceIdGenerator(be, ds, seqName, sequenceBatchSize);
+  public PlatformIdGenerator createSequenceIdGenerator(BackgroundExecutor be, DataSource ds, int increment, String seqName) {
+    return new DB2Sequence(be, ds, seqName, increment);
   }
 
 }

src/main/java/io/ebean/config/dbplatform/db2/DB2Sequence.java

@@ -0,0 +1,17 @@
+package io.ebean.config.dbplatform.db2;
+
+import io.ebean.BackgroundExecutor;
+import io.ebean.config.dbplatform.SequenceStepIdGenerator;
+
+import javax.sql.DataSource;
+
+/**
+ * DB2 specific sequence Id Generator.
+ */
+class DB2Sequence extends SequenceStepIdGenerator {
+
+  DB2Sequence(BackgroundExecutor be, DataSource ds, String seqName, int stepSize) {
+    super(be, ds, seqName, stepSize, "values nextval for " + seqName);
+  }
+
+}

src/main/java/io/ebean/config/dbplatform/h2/H2DbSequence.java

@@ -0,0 +1,14 @@
+package io.ebean.config.dbplatform.h2;
+
+import io.ebean.BackgroundExecutor;
+import io.ebean.config.dbplatform.SequenceStepIdGenerator;
+
+import javax.sql.DataSource;
+
+class H2DbSequence extends SequenceStepIdGenerator {
+
+  H2DbSequence(BackgroundExecutor be, DataSource ds, String seqName, int stepSize) {
+    super(be, ds, seqName, stepSize, "select " + seqName + ".nextval");
+  }
+
+}