Table Dropped or Truncated by Mistake?

Recover Dropped Tables Without Backup

Scenario Description

DROP TABLE or TRUNCATE has invalidated table files or the original object generation, without a directly restorable backup. If an image is preserved promptly and old InnoDB pages remain unoverwritten, DropScan can find recovery evidence.

Possible Causes

DROP TABLE was executed by mistake.
TRUNCATE was executed by mistake and original rows are inaccessible.
A table was recreated with the same name, mixing old and new object evidence.

Challenges

Conventional recovery often requires complete files, a running instance or a usable backup. In these situations, choose a method based on the evidence that survives.

Common Errors and Symptoms

- The table is missing or exists with no original rows.
- The directory lacks a complete old IBD.
- The disk image may retain original clustered pages.

Why Traditional Methods Fail

- An ordinary ROLLBACK cannot reverse committed DDL.
- Binlog records the DDL but may not contain every removed row.
- A recreated table cannot be merged with the old table by name alone.

PDU Solution

PDU scans surviving pages in the saved image. After confirming the original object generation, clustered index and matching DDL, it extracts recoverable rows. Normal rows, damaged content and missing dependencies are recorded separately. The surviving pages determine what can be recovered.

Recovery Principle

Stop New Writes
Preserve Disk Image
Bind Original Object
Extract Surviving Rows

PDU Core Capabilities

The original table need not remain in the instance directory.
Preserve page and metadata candidates.
Distinguish original and recreated object generations explicitly.
Parse clustered rows using matching DDL.
Retain reasons for external-value dependencies, missing pages and conflicts.
Native tasks support safe pause and resume.

Recovery Steps

1
Preserve the Disk Image Immediately
Before scanning, have the incident engineer preserve a stable disk image. Launch PDU outside the source files. Task records and exported output are saved in the launch directory.
Replace the example path, domain, generation and scan range with actual evidence. Use 0 for unknown domains and generations without inferring them.
2
Run ds idx First
Launch PDU in the result directory. ds idx reports DS_TASK. Replace <DS_TASK> in subsequent examples with the absolute task path from this run; do not specify another output directory.
ds idx preserves page and metadata candidates without exporting business data. Completion means only that the declared scan range was processed.
3
Obtain Table Structure
For version 8.0, select definitions from surviving SDI. Version 5.7 uses SYS_TABLES, SYS_INDEXES and matching FRM. Original DDL, Binlog Table_map and historical definitions can provide additional evidence; schema compatibility and business attribution are assessed separately.
4
Configure Table Structure Manually (If Needed)
Required Step
The numbers and DDL in the binding manifest are examples. Use actual source domain, generation, tablespace, clustered index and physical layout. STATIC does not replace INSTANT or hidden-column evidence.
5
Parse the Preserved Pages
Secondary-index, SDI and FULLTEXT auxiliary pages cannot be exported directly as complete business rows. Retain separate reasons for damaged pages, missing pages, opaque ciphertext and conflicts.
6
Restore External Large Values
LOB dependencies must come from matching tablespaces and object generations. When fragments or dependencies change, create a new recovery view with separate output and retain the parent view's native completion records.

Quick Command Examples

Preserve frozen sources and launch PDU outside them. Write configuration snippets to pdu.ini and execute PDU commands after startup. Replace example paths, versions, times and task identities with actual evidence.

# Preserve the Disk Image Immediately

PDU_DROPSCAN_SOURCES 1
source 1 image 1 1 cold-A "/recovery-input/disk.image" 0 0 512 16777216 31 1

# Run ds idx First

ds idx /recovery-input/sources.manifest;
ds show <DS_TASK> metadata;
ds show <DS_TASK> objects;

# Configure Table Structure Manually (If Needed)

PDU_DROPSCAN_BINDING 1
object "appdb.orders" 1 1 1 42 1234 16384 8 2 STATIC 268435456 0
evidence "Matching source generation and clustered-index evidence"
ddl
CREATE TABLE orders (id INT NOT NULL, value LONGBLOB, PRIMARY KEY (id)) ROW_FORMAT=DYNAMIC;

# Configure Table Structure Manually (If Needed)

ds bind <DS_TASK> /recovery-input/binding.manifest orders-A;

# Parse the Preserved Pages

ds unload <DS_TASK> orders-A;

Export Results

Pages and Bindings

Internal tasks record file sources, candidate pages, fixed bindings and object generations.

Recovered Data

Exported SQL is saved in the launch directory. Only records meeting the recovery rules are included in the normal output.

Quarantine and Checkpoints

Record damage, missing pages, ambiguity and historical dependencies separately, with native pause state retained.

After export, record PDU’s native success and failure counts and original errors, retaining checkpoints. Resume uses native records and file metadata without rereading exported data or automatic trial import.

Prerequisites

Stop new writes promptly after the incident and use a stable image or block source with consistency evidence.
Preserve source, object generation, clustered-index identity and table definitions. Names or tablespace IDs alone do not establish attribution.
Prepare a matching program, license and sufficient space. Keep original evidence read-only and place the PDU launch directory outside the sources.

Important Notes

Continued writes may overwrite old pages; protect the recovery scene first.
Secondary-index, SDI and FULLTEXT auxiliary pages are not complete business rows.
Finding page candidates does not recover the entire original table.

View Detailed Steps for This Recovery Method