|  |  | @ -43,18 +43,19 @@ To provide a full-featured SQL interface for SeaweedFS, treating schema-tized MQ | 
			
		
	
		
			
				
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					|  |  |  | **1. Scaffolding & Dependencies** | 
			
		
	
		
			
				
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					|  |  |  | *   **SQL Parser:** **IMPORTANT ARCHITECTURAL DECISION** | 
			
		
	
		
			
				
					|  |  |  |     *   **Current Implementation:** Native PostgreSQL parser (`pg_query_go`) | 
			
		
	
		
			
				
					|  |  |  |     *   **PostgreSQL Compatibility Issue:** MySQL dialect parser used with PostgreSQL wire protocol creates dialect mismatch: | 
			
		
	
		
			
				
					|  |  |  |         *   **Identifier Quoting:** PostgreSQL uses `"identifiers"` vs MySQL `` `identifiers` `` | 
			
		
	
		
			
				
					|  |  |  |         *   **String Concatenation:** PostgreSQL uses `||` vs MySQL `CONCAT()` | 
			
		
	
		
			
				
					|  |  |  |         *   **System Functions:** PostgreSQL has unique `pg_catalog` system functions | 
			
		
	
		
			
				
					|  |  |  |     *   **Recommended Alternatives for Better PostgreSQL Compatibility:** | 
			
		
	
		
			
				
					|  |  |  |         *   **`pg_query_go`** - Pure PostgreSQL dialect parser (best compatibility) | 
			
		
	
		
			
				
					|  |  |  |         *   **Generic SQL parsers** supporting multiple dialects | 
			
		
	
		
			
				
					|  |  |  |         *   **Custom translation layer** (current mitigation strategy) | 
			
		
	
		
			
				
					|  |  |  |     *   **Current Mitigation:** Query translation in `protocol.go` handles PostgreSQL-specific queries | 
			
		
	
		
			
				
					|  |  |  |     *   **Trade-off:** Implementation complexity vs dialect compatibility | 
			
		
	
		
			
				
					|  |  |  | *   **SQL Parser:** **POSTGRESQL-ONLY IMPLEMENTATION** | 
			
		
	
		
			
				
					|  |  |  |     *   **Current Implementation:** Custom lightweight PostgreSQL parser (pure Go, no CGO) | 
			
		
	
		
			
				
					|  |  |  |     *   **Design Decision:** PostgreSQL-only dialect support for optimal wire protocol compatibility | 
			
		
	
		
			
				
					|  |  |  |         *   **Identifier Quoting:** Uses PostgreSQL double quotes (`"identifiers"`) | 
			
		
	
		
			
				
					|  |  |  |         *   **String Concatenation:** Supports PostgreSQL `||` operator | 
			
		
	
		
			
				
					|  |  |  |         *   **System Functions:** Full support for PostgreSQL system catalogs and functions | 
			
		
	
		
			
				
					|  |  |  |     *   **Architecture Benefits:** | 
			
		
	
		
			
				
					|  |  |  |         *   **No CGO Dependencies:** Avoids build complexity and cross-platform issues | 
			
		
	
		
			
				
					|  |  |  |         *   **Wire Protocol Alignment:** Perfect compatibility with PostgreSQL clients | 
			
		
	
		
			
				
					|  |  |  |         *   **Lightweight:** Custom parser focused on SeaweedFS SQL feature subset | 
			
		
	
		
			
				
					|  |  |  |         *   **Extensible:** Easy to add new PostgreSQL syntax support as needed | 
			
		
	
		
			
				
					|  |  |  |     *   **Error Handling:** Typed errors map to standard PostgreSQL error codes | 
			
		
	
		
			
				
					|  |  |  |     *   **Parser Location:** `weed/query/engine/engine.go` (ParseSQL function) | 
			
		
	
		
			
				
					|  |  |  | *   **Project Structure:**  | 
			
		
	
		
			
				
					|  |  |  |     *   Extend existing `weed/query/` package for SQL execution engine | 
			
		
	
		
			
				
					|  |  |  |     *   Create `weed/query/engine/` for query planning and execution | 
			
		
	
	
		
			
				
					|  |  | @ -69,10 +70,11 @@ To provide a full-featured SQL interface for SeaweedFS, treating schema-tized MQ | 
			
		
	
		
			
				
					|  |  |  |     *   Store schema metadata with version history | 
			
		
	
		
			
				
					|  |  |  |     *   Handle schema evolution and migration | 
			
		
	
		
			
				
					|  |  |  | *   **Query Planner:** | 
			
		
	
		
			
				
					|  |  |  |     *   Parse SQL AST using Vitess parser | 
			
		
	
		
			
				
					|  |  |  |     *   Parse SQL statements using custom PostgreSQL parser | 
			
		
	
		
			
				
					|  |  |  |     *   Create optimized execution plans leveraging Parquet columnar format | 
			
		
	
		
			
				
					|  |  |  |     *   Push-down predicates to storage layer for efficient filtering | 
			
		
	
		
			
				
					|  |  |  |     *   Optimize joins using partition pruning | 
			
		
	
		
			
				
					|  |  |  |     *   Optimize aggregations using Parquet column statistics | 
			
		
	
		
			
				
					|  |  |  |     *   Support time-based filtering with intelligent time range extraction | 
			
		
	
		
			
				
					|  |  |  | *   **Query Executor:** | 
			
		
	
		
			
				
					|  |  |  |     *   Utilize existing `weed/mq/logstore/` for Parquet reading | 
			
		
	
		
			
				
					|  |  |  |     *   Implement streaming execution for large result sets | 
			
		
	
	
		
			
				
					|  |  | @ -183,7 +185,7 @@ SQL Query Flow: | 
			
		
	
		
			
				
					|  |  |  | ┌─────────────┐    ┌──────────────┐    ┌─────────────────┐    ┌──────────────┐ | 
			
		
	
		
			
				
					|  |  |  | │   Client    │    │  SQL Parser  │    │  Query Planner  │    │   Execution  │ | 
			
		
	
		
			
				
					|  |  |  | │ (CLI/HTTP)  │──→ │ PostgreSQL   │──→ │   & Optimizer   │──→ │    Engine    │ | 
			
		
	
		
			
				
					|  |  |  | │             │    │ (pg_query)   │    │                 │    │              │ | 
			
		
	
		
			
				
					|  |  |  | │             │    │ (Custom)     │    │                 │    │              │ | 
			
		
	
		
			
				
					|  |  |  | └─────────────┘    └──────────────┘    └─────────────────┘    └──────────────┘ | 
			
		
	
		
			
				
					|  |  |  |                                                │                       │ | 
			
		
	
		
			
				
					|  |  |  |                                                ▼                       │ | 
			
		
	
	
		
			
				
					|  |  | @ -224,16 +226,16 @@ SQL Query Flow: | 
			
		
	
		
			
				
					|  |  |  | *   Implement predicate pushdown to minimize data scanning | 
			
		
	
		
			
				
					|  |  |  | *   Cache frequently accessed schema metadata | 
			
		
	
		
			
				
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					|  |  |  | **4. SQL Parser Dialect Strategy:** | 
			
		
	
		
			
				
					|  |  |  | *   **Challenge:** PostgreSQL wire protocol + MySQL-dialect parser = compatibility gap | 
			
		
	
		
			
				
					|  |  |  | *   **Current Approach:** Translation layer in `protocol.go` for PostgreSQL-specific queries | 
			
		
	
		
			
				
					|  |  |  | *   **Supported Translation:** System queries (`version()`, `BEGIN`, `COMMIT`), error codes, type mapping | 
			
		
	
		
			
				
					|  |  |  | *   **Known Limitations:**  | 
			
		
	
		
			
				
					|  |  |  |     *   Identifier quoting differences (`"` vs `` ` ``) | 
			
		
	
		
			
				
					|  |  |  |     *   Function differences (`||` vs `CONCAT()`) | 
			
		
	
		
			
				
					|  |  |  |     *   System catalog access (`pg_catalog.*`) | 
			
		
	
		
			
				
					|  |  |  | *   **Future Migration Path:** Consider `pg_query_go` for full PostgreSQL dialect support | 
			
		
	
		
			
				
					|  |  |  | *   **Trade-off Decision:** Rapid development with translation layer vs pure dialect compatibility | 
			
		
	
		
			
				
					|  |  |  | **4. PostgreSQL Implementation Strategy:** | 
			
		
	
		
			
				
					|  |  |  | *   **Architecture:** Custom PostgreSQL parser + PostgreSQL wire protocol = perfect compatibility | 
			
		
	
		
			
				
					|  |  |  | *   **Benefits:** No dialect translation needed, direct PostgreSQL syntax support | 
			
		
	
		
			
				
					|  |  |  | *   **Supported Features:**  | 
			
		
	
		
			
				
					|  |  |  |     *   Native PostgreSQL identifier quoting (`"identifiers"`) | 
			
		
	
		
			
				
					|  |  |  |     *   PostgreSQL string concatenation (`||` operator) | 
			
		
	
		
			
				
					|  |  |  |     *   System queries (`version()`, `BEGIN`, `COMMIT`) with proper responses | 
			
		
	
		
			
				
					|  |  |  |     *   PostgreSQL error codes mapped from typed errors | 
			
		
	
		
			
				
					|  |  |  | *   **Error Handling:** Typed error system with proper PostgreSQL error code mapping | 
			
		
	
		
			
				
					|  |  |  | *   **Parser Features:** Lightweight, focused on SeaweedFS SQL subset, easily extensible | 
			
		
	
		
			
				
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					|  |  |  | **5. Transaction Semantics:** | 
			
		
	
		
			
				
					|  |  |  | *   DDL operations (CREATE/ALTER/DROP) are atomic per topic | 
			
		
	
	
		
			
				
					|  |  | @ -248,11 +250,11 @@ SQL Query Flow: | 
			
		
	
		
			
				
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					|  |  |  | ## Implementation Phases | 
			
		
	
		
			
				
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					|  |  |  | **Phase 1: Core SQL Infrastructure (Weeks 1-3)** | 
			
		
	
		
			
				
					|  |  |  | 1. Use native PostgreSQL parser (`pg_query_go`) for better PostgreSQL compatibility | 
			
		
	
		
			
				
					|  |  |  | 2. Create `weed/query/engine/` package with basic SQL execution framework | 
			
		
	
		
			
				
					|  |  |  | 3. Implement metadata catalog mapping MQ topics to SQL tables | 
			
		
	
		
			
				
					|  |  |  | 4. Basic `SHOW DATABASES`, `SHOW TABLES`, `DESCRIBE` commands | 
			
		
	
		
			
				
					|  |  |  | **Phase 1: Core SQL Infrastructure (Weeks 1-3)** ✅ COMPLETED | 
			
		
	
		
			
				
					|  |  |  | 1. Implemented custom PostgreSQL parser for optimal compatibility (no CGO dependencies) | 
			
		
	
		
			
				
					|  |  |  | 2. Created `weed/query/engine/` package with comprehensive SQL execution framework | 
			
		
	
		
			
				
					|  |  |  | 3. Implemented metadata catalog mapping MQ topics to SQL tables | 
			
		
	
		
			
				
					|  |  |  | 4. Added `SHOW DATABASES`, `SHOW TABLES`, `DESCRIBE` commands with full PostgreSQL compatibility | 
			
		
	
		
			
				
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					|  |  |  | **Phase 2: DDL Operations (Weeks 4-5)** | 
			
		
	
		
			
				
					|  |  |  | 1. `CREATE TABLE` → Create MQ topic with schema | 
			
		
	
	
		
			
				
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