optimize DBCL checksum query and set fetch size on all statements (DAT-17267)

liquibase-standard/src/main/java/liquibase/changelog/StandardChangeLogHistoryService.java

@@ -245,14 +245,12 @@ public void init() throws DatabaseException {
             }
 
             SqlStatement databaseChangeLogStatement = new SelectFromDatabaseChangeLogStatement(
-                    new SelectFromDatabaseChangeLogStatement.ByNotNullCheckSum(),
+                    new SelectFromDatabaseChangeLogStatement.ByCheckSumNotNullAndNotLike(ChecksumVersion.latest().getVersion()),
                     new ColumnConfig().setName("MD5SUM"));
             List<Map<String, ?>> md5sumRS = ChangelogJdbcMdcListener.query(getDatabase(), ex -> ex.queryForList(databaseChangeLogStatement));
 
-            if (!md5sumRS.isEmpty()) {
-                //check if any checksum is not using the current version
-                databaseChecksumsCompatible = md5sumRS.stream().allMatch(m -> m.get("MD5SUM").toString().startsWith(ChecksumVersion.latest().getVersion() + ":"));
-            }
+            //check if any checksum is not using the current version
+            databaseChecksumsCompatible = md5sumRS.isEmpty();
 
 
         } else if (!changeLogCreateAttempted) {

liquibase-standard/src/main/java/liquibase/executor/jvm/JdbcExecutor.java

@@ -75,6 +75,9 @@ public Object execute(StatementCallback action, List<SqlVisitor> sqlVisitors) th
                 throw new DatabaseException("Cannot execute commands against an offline database");
             }
             stmt = ((JdbcConnection) con).getUnderlyingConnection().createStatement();
+            if (Boolean.TRUE.equals(SqlConfiguration.ALWAYS_SET_FETCH_SIZE.getCurrentValue())) {
+                stmt.setFetchSize(database.getFetchSize());
+            }
             Statement stmtToUse = stmt;
 
             Object object = action.doInStatement(stmtToUse);

liquibase-standard/src/main/java/liquibase/sql/SqlConfiguration.java

@@ -14,6 +14,8 @@ public class SqlConfiguration implements AutoloadedConfigurations {
     public static final ConfigurationDefinition<Level> SHOW_AT_LOG_LEVEL;
     public static final ConfigurationDefinition<Boolean> SHOW_SQL_WARNING_MESSAGES;
 
+    public static final ConfigurationDefinition<Boolean> ALWAYS_SET_FETCH_SIZE;
+
     static {
         ConfigurationDefinition.Builder builder = new ConfigurationDefinition.Builder("liquibase.sql");
 
@@ -26,5 +28,10 @@ public class SqlConfiguration implements AutoloadedConfigurations {
                 .setDescription("Show SQLWarning messages")
                 .setDefaultValue(Boolean.TRUE)
                 .build();
+        ALWAYS_SET_FETCH_SIZE = builder.define("alwaysSetFetchSize", Boolean.class)
+                .setDescription("If true, all queries will have their fetch size set to the fetch size defined in their database implementation. This has the effect of informing the driver how many rows should be fetched when processing the result set. This is not guaranteed to be respected by the driver, but if respected, should improve query performance significantly.")
+                .setDefaultValue(Boolean.TRUE)
+                .setHidden(true)
+                .build();
     }
 }

liquibase-standard/src/main/java/liquibase/sqlgenerator/core/SelectFromDatabaseChangeLogGenerator.java

@@ -3,12 +3,7 @@
 import liquibase.change.ColumnConfig;
 import liquibase.database.Database;
 import liquibase.database.ObjectQuotingStrategy;
-import liquibase.database.core.AbstractDb2Database;
-import liquibase.database.core.MSSQLDatabase;
-import liquibase.database.core.MySQLDatabase;
-import liquibase.database.core.OracleDatabase;
-import liquibase.database.core.PostgresDatabase;
-import liquibase.exception.UnexpectedLiquibaseException;
+import liquibase.database.core.*;
 import liquibase.exception.ValidationErrors;
 import liquibase.sql.Sql;
 import liquibase.sql.UnparsedSql;
@@ -48,13 +43,7 @@ public Sql[] generateSql(SelectFromDatabaseChangeLogStatement statement, final D
 
             SelectFromDatabaseChangeLogStatement.WhereClause whereClause = statement.getWhereClause();
             if (whereClause != null) {
-                if (whereClause instanceof SelectFromDatabaseChangeLogStatement.ByTag) {
-                    sql += " WHERE "+database.escapeColumnName(null, null, null, "TAG")+"='" + ((SelectFromDatabaseChangeLogStatement.ByTag) whereClause).getTagName() + "'";
-                } else if (whereClause instanceof SelectFromDatabaseChangeLogStatement.ByNotNullCheckSum) {
-                    sql += " WHERE "+database.escapeColumnName(null, null, null, "MD5SUM")+" IS NOT NULL";
-                } else {
-                    throw new UnexpectedLiquibaseException("Unknown where clause type: " + whereClause.getClass().getName());
-                }
+                sql += whereClause.generateSql(database);
             }
 
             if ((statement.getOrderByColumns() != null) && (statement.getOrderByColumns().length > 0)) {

liquibase-standard/src/main/java/liquibase/statement/core/SelectFromDatabaseChangeLogStatement.java

@@ -1,7 +1,10 @@
 package liquibase.statement.core;
 
 import liquibase.change.ColumnConfig;
+import liquibase.database.Database;
 import liquibase.statement.AbstractSqlStatement;
+import lombok.Data;
+import lombok.Getter;
 
 public class SelectFromDatabaseChangeLogStatement extends AbstractSqlStatement {
 
@@ -57,12 +60,19 @@ public SelectFromDatabaseChangeLogStatement setLimit(Integer limit) {
 
     public interface WhereClause {
 
+        String generateSql(Database database);
+
     }
 
     public static class ByNotNullCheckSum implements WhereClause {
 
+        @Override
+        public String generateSql(Database database) {
+            return String.format(" WHERE %s IS NOT NULL", database.escapeColumnName(null, null, null, "MD5SUM"));
+        }
     }
 
+    @Getter
     public static class ByTag implements WhereClause {
 
         private final String tagName;
@@ -71,8 +81,20 @@ public ByTag(String tagName) {
             this.tagName = tagName;
         }
 
-        public String getTagName() {
-            return tagName;
+        @Override
+        public String generateSql(Database database) {
+            return String.format(" WHERE %s='%s'", database.escapeColumnName(null, null, null, "TAG"), getTagName());
+        }
+    }
+
+    @Data
+    public static class ByCheckSumNotNullAndNotLike implements WhereClause {
+        private final int notLikeCheckSumVersion;
+
+        @Override
+        public String generateSql(Database database) {
+            final String md5SUMColumnName = database.escapeColumnName(null, null, null, "MD5SUM");
+            return String.format(" WHERE %s IS NOT NULL AND %s NOT LIKE '%d:%%'", md5SUMColumnName, md5SUMColumnName, notLikeCheckSumVersion);
         }
     }