[Docs] Restructure certain sections under Explore

[aishwarya24]

Description

• Rename Distributed SQL features to SQL features.
• Since SQL features should comprise of SQL only features under it , move indexes after transactions.

Here's just how the ordering will possibly look like in Explore . @rkarthik007 , please validate.

Explore

• SQL features (add "Unsupported features" section in this page)
  1. Schemas and Tables
  2. Data Types
  3. Data Manipulation
  4. Queries and Joins
  5. Expressions and Operators
  6. Stored Procedures
  7. Triggers
  8. Advanced features Cursors Table Partitioning Views Savepoints Collations Extensions
  9. Going Beyond SQL Data distribution with HASH Tablespaces Follower Reads TABLEGROUPs

• Fault tolerance ( TODO: rename to Continuous Availability and add more content)
  • Handling Failures --> Run TPC-C or YCSB, take a node down, show impact on app and server side graphs. Similarly, show impact of zone failure on a 9 node cluster (3 nodes per zone). Talk about the following: how transactions rebalance across other nodes evenly when one node fails, RPO/RTO of a multi-zone deployment on failures, touch on how to distribute queries from app layer (smart driver or load balancer)
  • Auto Resilience --> If a node remains down, data is automatically re-replicated onto other nodes. Talk about how fault domains are respected.
  • Software upgrades --> Upgrade one node at a time, show impact on app and server side graphs
  • Security Patching (stretch goal)
• Horizontal scalability
  • Scaling transactions (TPC-C - effect of adding a node)
  • Scaling data sets (YSQL and YCQL)
  • Scaling connections (stretch goal)
• Transactions
  • Add READ COMMITTED isolation level
  • Transactionality of DDLs - what happens if a column is added to a table in the middle of a txn.
  • Add optimistic vs pessimistic concurrency control when ready
• Indexes and Constraints
  • Primary Key (YSQL and YCQL)
  • Foreign Key (YSQL)
  • Other Constraints (YSQL)
  • Unique Index (YSQL and YCQL)
  • Partial Index (YSQL and YCQL)
  • Expression Index (YSQL)
  • GIN Index (YSQL)
• JSON support
  • Need a pointer to GIN indexes
  • Do we need to add text search here?
• Multi-region deployments (TPC-C examples for each type of replication - with latency and throughput for each)
  • Sync replication
  • Async Replication
  • Bidirectional Async Replication
  • Geo-partitioning
  • Read Replicas
• Query Tuning
• Cluster management
  • Index rebuild (and drop) on the fly
  • Distributed backup and restore
  • PITR
  • Rolling upgrades
  • AMI refresh
• CDC (when we have it )
• Security
• Observability
  • How to setup prometheus
  • How to setup a Grafana dashboard

[ymahajan]

We can also add Orchestration/K8S

[aishwarya24]

@ymahajan Sure, does Cluster management looks like a good section where we can probably add an overview of how it can be done?

[polarweasel]

CDC will be in the Core Database section within a day or two, at /latest/cdc/ for now