Windsoft / Querydog / Basis for DB Migration Function
Querydog DB-to-DB Migration: Implemented Functions and Verification Scope
Querydog is not just a tool that provides clipboard paste functionality. It has a transfer function that reads rows from the source DB in batches and loads them into the target DB. However, it does not claim that all migrations are automatically lossless, high-speed, or fully verified.
Five frequently compared items
| Items | Contents confirmed in Querydog | Scope and verification materials |
|---|---|---|
| Data transfer between DBs | A separate work thread reads multiple rows at once from the source DB cursor and performs batch INSERT into the target DB. There are regenerate, synchronize, and incremental modes, and DDL and data transfer are executed with separate buttons. | Explanation and screen of DDL/Data transfer. The explanation that it copies to the clipboard and pastes manually differs from the actual implementation. |
| Interruption/Partial transfer | If source reading is interrupted, it stops at the current table and marks the subsequent tables as unprocessed. Tables with failed rows or truncated values are excluded from success and remain for re-verification. | Retry procedure after interruption. Rows already committed may remain in the target, and it does not automatically declare completion as lossless. |
| Data type conversion | Oracle’s NUMBER(p,s)to MariaDB/MySQL’s DECIMAL(p,s)There are automatic rules such as converting to. Before applying the generated CREATE TABLE, you can check the original type, automatic suggestions, and warnings for each column, and modify and save the target type. | Type Review Procedure. Reducing precision or character length triggers a warning but does not guarantee lossless conversion of the actual data. Existing target columns are not automatically ALTERed. |
| Large-scale Processing | Data is read and loaded in batches. The default batch size for a normal path is 5,000 rows, and smaller sizes are used depending on the DB and LOB type. | Batch Transfer Explanation. 2026-10-27 MariaDB 6.38 million rows DBeaver comparison recordhas been published. Each execution is one time and there are internal setting differences. Maximum memory was not measured. |
| Foreign Keys (FK) | The original FK relationships are analyzed to determine an order to load parent tables first. Some copy paths targeting MariaDB/MySQL temporarily disable FK and unique key checks in the session. | Transfer Order Guide. While FK checks are turned off, incorrect references may be entered. Do not assume that all FK orphan rows are automatically proven to be zero after transfer. |
| Community·Pro | Community is free and supports basic heterogeneous DDL and data transfer, including Oracle→MariaDB. Incremental transfer, permission copying, transfer scheduling, and Oracle PL/SQL migration are Pro features. | Features by Mode. The explanation that “Querydog’s cross-database transfer is all paid” is not accurate. |
Retry range when connection is lost
After restoring the source connection and resolving the cause of the error, reselect the remaining parts of the result transfer or unprocessed tables. If there is a matching PK/UNIQUE key in the source and target, synchronization supplements keys missing in the target by comparison. To reflect modifications of existing rows, a separate existing row update option is required.
If there is no key or the keys on both sides are different, synchronization blocks the corresponding table. Selecting regeneration at this point may delete existing rows in the target, so the user must decide whether to preserve the target. Querydog does not automatically resume from the position of the interrupted source cursor, and synchronization alone does not guarantee deletion history or complete value matching of the original.
Scope of Querydog Community and Pro
Community is the free usage range of Querydog, not a separate installation file. If you have a Pro license, additional functions are unlocked in the same program. Providing Community under an open-source license is not implied.
| Features | Community (Free) | Pro |
|---|---|---|
| DB connection, SQL editing, table data editing, import/export | Available | Available |
| Basic DDL and data transfer for homogeneous/heterogeneous DBs | Regeneration and synchronization modes available | Available |
| Transfer comparison and validation report | Available. Comparison range depends on the results of the operation | Available |
| Incremental transfer, transfer scheduling, permission copying | Not provided | Available |
| Oracle PL/SQL migration, DB structure comparison | Not provided | Available |
Target DB and detailed constraints for the features are User manualPlease check. The scope of free provision and the terms of use are different issues, and this page does not separately guarantee commercial usage rights or source disclosure.
Compared to DBeaver
DBeaver Community has a data migration wizard between DBs. The official documentation specifies options such as modifying target column types, setting maximum thread count and read size, and disabling constraint checks for supported DBs. Community is a free open-source product. This does not mean that Querydog provides the same level of detailed adjustment screens or parallel processing performance.
DBeaver Data Migration Official Documentation · DBeaver Community License
To determine which of the two products is faster or safer, measurements must be made using the same source and target DB, data, equipment, network, constraints, and validation scope. The expression “no data loss” is not guaranteed just by the product name.
Oracle → MariaDB PL/SQL Conversion Test
On October 31, 2026, Querydog 1.0.45 source was tested on the Oracle test schema and a separate MariaDB validation DB. Collected objects 40/40 were compiled as DDLDone, new test routine 10/10The specified input results and the four existing business date functions 259/259 input resultswere checked.
This figure is the result of the PL/SQL conversion test scope and does not represent the migration rate of table data, the entire business functions, or external call parts. Oracle TYPE and PIPELINED functions need to be replaced with JSON functions or result set procedures in MariaDB, requiring a change in the way they are called.
Object composition, results by version, verification methods, and remaining risk assessment
How to check directly
- Prepare the test Oracle source and MariaDB target, and PK·FK,
NUMBER, Select a table that has Hangul, NULL, and CLOB/BLOB. - After checking the DDL preview in Querydog, send the structure and select the data copy mode to perform the task. Screen guidePlease refer to.
- Transmission result and Verification ReportCheck it. Do not judge that all values and FK references match just because the number of rows is the same.
- If necessary, separate comparisons of values by PK and checks for orphaned rows of target FKs are performed on the same original snapshot. Processing time and maximum memory are recorded to compare with other tools under the same conditions.
The screen images in the user manual are examples of the product UI and are not test records that demonstrate the actual results of large-scale transfers from Oracle to MariaDB. Separate from the PL/SQL conversion test, the lossless and operational suitability of large-scale data transfers must be verified according to the test conditions.
Introduction to Querydog products · User manual
Querydog vs DBeaver transfer speed comparison — measured in 11 directions for MariaDB, Oracle, PostgreSQL, MSSQL, SQLiteCheck transfer time, bulk load settings, pre- and post-improvement results, and data validation scope.
Querydog Community (community) is free. Pro is the paid edition that provides additional features. Check the differences between free Community features and Pro