Summary

Enable per-tenant TTL on multi-tenant base tables by letting a tenant create a view (with or without a WHERE clause) and set TTL on it. Read masking and compaction use the existing View TTL infrastructure.

Changes

• WhereOptimizer.getRowKeyMatcher: compute ROW_KEY_MATCHER from the connection's tenant-id when a tenant view is created without a WHERE clause, so it participates in the compaction RowKeyMatcher trie. Wraps ScanUtil.getTenantIdBytes in try/catch to avoid breaking creation when the tenant-id type doesn't match the schema.
• CreateTableCompiler.compile: always invoke getRowKeyMatcher for UPDATABLE views (no longer gated on where != null).

New validation (ViewUtil.validateTenantViewWithoutWhereTTLCoexistence)

On a multi-tenant base table, among a given tenant's views without a WHERE clause, we allow either:

• (a) any number of no-WHERE views without TTL, or
• (b) exactly one no-WHERE view with TTL.
  Multiple no-WHERE TTL views share the same ROW_KEY_MATCHER (tenant-id bytes) and would conflict in the compaction RowKeyMatcher trie. The check rejects such operations with TENANT_VIEW_WITHOUT_WHERE_TTL_CONFLICT. Views with WHERE clauses are out of scope for this check (their prefix-conflict potential is a pre-existing concern tracked separately).
  The helper lives in ViewUtil and is invoked from:
• CREATE VIEW (CreateTableCompiler) when creating a no-WHERE view on a multi-tenant base table.
• ALTER VIEW SET TTL (MetaDataClient.evaluateStmtProperties) when the view being altered is a no-WHERE tenant view on a multi-tenant base table; the view itself is excluded from the sibling check.
  Gracefully skips when CHILD_LINK is unavailable (namespace mapping edge cases) or in connectionless mode (unit tests).

Tests (TenantTTLIT)

• testReadMaskingWithDifferentTenantTTLs
• testCompactionWithDifferentTenantTTLs — INTEGER non-tenant PK
• testThreeTenantsDifferentTTLs — CHAR(3) + BIGINT PK columns
• testCompactionWithSplitRegions — pre-split base table
• testCompactionWithSaltedMultiTenantTable
• testCompactionWithTenantTableIndex — with secondary index on the base table
• testSameViewNameAcrossDifferentTenants
• testTenantTTLWithUpdatableViewRestrictionEnabled
• testTenantTTLViewCoexistenceRules — 9 cases exercising every CREATE-path branch (no-WHERE non-TTL, no-WHERE TTL, mixed, different tenants, newly-allowed WHERE-scoped creations)
• testAlterTTLOnTenantViewWithSiblingIsRejected — ALTER-path rejection for no-WHERE views
• testAlterTTLOnWhereScopedTenantViewIsAllowed — ALTER-path allowed for WHERE-scoped views
• testAlterTenantViewToAddTTL — ALTER TTL masking/compaction end-to-end
• testChildViewsOfTenantTTLViewInheritTTL — child views inherit parent tenant view's TTL