> ## Documentation Index > Fetch the complete documentation index at: https://planetscale.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Settings > Postgres settings that control TIN. export const PlatformAvailability = ({current, vitess, postgres, neki}) => { const docsHref = path => { if (!path) return path; const normalized = path.startsWith('/') ? path : `/${path}`; return normalized; }; const labels = { vitess: 'Vitess', postgres: 'Postgres', neki: 'Neki' }; const combinedLabels = { both: 'Vitess and Postgres', all: 'Vitess, Neki, and Postgres', 'postgres-neki': 'Postgres and Neki' }; if (combinedLabels[current]) { return
{combinedLabels[current]}
; } const hasVitess = current === 'vitess' || Boolean(vitess); const hasPostgres = current === 'postgres' || Boolean(postgres); const hasNeki = current === 'neki' || Boolean(neki); const only = [hasVitess, hasPostgres, hasNeki].filter(Boolean).length === 1; const engines = []; if (current === 'vitess' || current === 'postgres' || current === 'neki') engines.push(current); if (hasVitess && current !== 'vitess') engines.push('vitess'); if (hasNeki && current !== 'neki') engines.push('neki'); if (hasPostgres && current !== 'postgres') engines.push('postgres'); return
{engines.map(engine => { const isCurrent = current === engine; const href = docsHref(engine === 'vitess' ? vitess : engine === 'postgres' ? postgres : neki); const label = only ? `${labels[engine]} only` : labels[engine]; const state = isCurrent || !href ? 'current' : 'link'; if (isCurrent || !href) { return {label} ; } return {label} ; })}
; }; These are ordinary Postgres GUCs (`SET`, `ALTER DATABASE … SET`, or `postgresql.conf`). Defaults are tuned for good performance, and you usually do not need to change them. | Setting | Default | Notes | | ----------------------------- | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `tin.enable_custom_scan` | `on` | When `off`, falls back to generic index scanning (troubleshooting / comparison). | | `tin.index_maintenance_mode` | `background` | How index maintenance runs: `background`, `foreground` (in the writing session), or `manual` (no automatic maintenance). | | `tin.build_io_concurrency` | `0` (auto) | Caps concurrent disk I/O during `CREATE INDEX` / `REINDEX`. `1` serializes build I/O. | | `tin.rss_baseline` | server-derived (MB) | Per-worker RSS estimate used when planning build parallelism. | | `tin.maintenance_jobs_per_db` | `0` | How many of its own database's maintenance jobs a cluster-wide maintenance worker finishes before yielding to another database with queued work. `0` drains the current database first. Set it in `postgresql.conf` or with `ALTER SYSTEM`. A session `SET` is rejected. | | `tin.track_page_reuse_stats` | `off` | When `on`, `EXPLAIN ANALYZE` reports distinct vs repeated index page reads. | ## Debug settings The `tin.debug_*` settings are for debugging and testing TIN, not for production use. Each one forces a planning choice the cost model would otherwise make, so that an alternative plan can be measured. They never change query results, and a query shape that would be incorrect is still refused. All of them are session-level (`SET`) and default to following the cost model. | Setting | Values | Default | Notes | | ----------------------------------- | ------------------------------------------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------------- | | `tin.debug_force_boolean_family` | `auto`, `fused`, `factored` | `auto` | For a query over several TIN indexes, force one combined scan (`fused`) or separate scans joined with boolean operators (`factored`). | | `tin.debug_force_topk` | `auto`, `topk`, `exhaustive` | `auto` | For `ORDER BY tin.score(ctid) DESC LIMIT k`, force the bounded top-k scan or an exhaustive scored scan. | | `tin.debug_force_multi_index_drive` | `auto`, `sparse`, `stripe` | `auto` | For a query over several TIN indexes, drive from the rarest required term (`sparse`) or evaluate by block range (`stripe`). | | `tin.debug_force_conjunction_mode` | `auto`, `generic`, `pushdown`, `noadaptive` | `auto` | Override how an `AND` between a text predicate and another indexed predicate is executed. `noadaptive` only disables the adaptive verifier. | | `tin.debug_force_visibility` | `auto`, `streaming`, `sorted` | `auto` | Where a count-only `AND` can check row visibility in streaming or sorted order, force one. | | `tin.debug_disable_count_pushdown` | `on`, `off` | `off` | Disable the index-answered `count(*)` path so a plain aggregate over a scan runs instead. | | `tin.debug_disable_index_probe` | `on`, `off` | `off` | Disable probing a btree index alongside the text search; mixed predicates fall back to a TIN scan with Postgres filters. | | `tin.debug_force_parallel` | `on`, `off` | `off` | Drop serial plans that have a parallel sibling so the parallel plan is chosen, including on tables too small to qualify otherwise. | ## Need help? Get help from [the PlanetScale Support team](https://planetscale.com/contact?initial=support), or join our [Discord community](https://pscale.link/community) to see how others are using PlanetScale.