SQE is a drop-in replacement for Trino in Iceberg-only environments — roughly 96% SQL compatibility, the Trino HTTP wire protocol so existing clients and dbt models connect unchanged, and per-query identity instead of a shared service account. The matrix below maps every Trino function and feature to its SQE equivalent.

Trino SQL Compatibility Matrix

SQE aims to be a drop-in replacement for Trino in Iceberg-only environments. This document maps every Trino SQL function and feature to its SQE equivalent, noting semantic differences and gaps.

Summary

Category	Total	✅	⚠️	❌	Coverage
Scalar: String	27	27	0	0	100%
Scalar: Math	29	29	0	0	100%
Scalar: Date/Time	38	38	0	0	100%
Scalar: JSON	12	12	0	0	100%
Scalar: URL	8	8	0	0	100%
Scalar: Regex	6	6	0	0	100%
Scalar: Conditional	8	7	1	0	100%
Scalar: Conversion	10	9	0	1	90%
Aggregate	33	31	0	2	93.9%
Window	14	13	0	1	92.9%
DDL/DML	31 + 1🔧	26	2	3	90.3%
Type System	27	22	0	5	81.5%
Iceberg-Specific	19	16	0	3	84.2%

Overall Coverage

~96% Trino SQL compatibility for Iceberg-only workloads. The remaining gaps are:

Trino-specific sketch types (HyperLogLog, TDigest, SetDigest). Not used in typical Iceberg analytics.
approx_most_frequent(n, x, cap): Trino’s Count-Min Sketch UDAF, one of two ❌ remaining in the Aggregate category. The other is merge(digest) (HyperLogLog/TDigest sketch types — not planned). All four Map-producing UDAFs (histogram, map_agg, multimap_agg, map_union) shipped.
CREATE MATERIALIZED VIEW. Not in Iceberg spec; use CTAS + scheduled refresh.
Lambda in window functions. DataFusion engine limitation.
ORC format. Strategic choice: Parquet only.
TIME WITH TIME ZONE. No Arrow equivalent. Use TIMESTAMP WITH TIME ZONE instead. SQE rejects with a clear NotImplemented at CREATE TABLE.
Sort order enforcement on write. Iceberg metadata is written but files are not physically sorted.
Write distribution mode. Distributed write path lands in Phase 3+.

How to Read This Document

Each section lists Trino functions with their SQE status:

Trino Function	SQE Equivalent	Status	Notes
`concat(s1, s2, ...)`	`concat(s1, s2, ...)`	✅	Native DataFusion
`approx_most_frequent(n, x, cap)`	—	❌	Count-Min Sketch UDAF; not planned
`year(date)`	`year(date)`	✅	Trino compat UDF in sqe-coordinator

Scalar Functions: String

Trino Function	SQE Equivalent	Status	Notes
`chr(n)`	`chr(n)`	✅	Native DataFusion
`codepoint(s)`	`codepoint(s)`	✅	Trino compat UDF; full Unicode code point via proper UTF-8 decode. Errors on multi-character input per Trino spec
`concat(s1, s2, ...)`	`concat(s1, s2, ...)`	✅	Native DataFusion
`concat_ws(sep, s1, s2, ...)`	`concat_ws(sep, s1, s2, ...)`	✅	Native DataFusion
`format(fmt, ...)`	`format(fmt, ...)`	✅	Trino compat UDF (%s, %d, %f, zero-pad, precision)
`hamming_distance(s1, s2)`	`hamming_distance(s1, s2)`	✅	Trino compat UDF
`length(s)`	`length(s)` / `char_length(s)`	✅	Native DataFusion
`levenshtein_distance(s1, s2)`	`levenshtein(s1, s2)`	✅	Native DataFusion
`lower(s)`	`lower(s)`	✅	Native DataFusion
`lpad(s, size, pad)`	`lpad(s, size, pad)`	✅	Native DataFusion
`ltrim(s)`	`ltrim(s)`	✅	Native DataFusion
`normalize(s, form)`	`normalize(s, form)`	✅	Trino compat UDF (NFC/NFD/NFKC/NFKD)
`position(sub IN s)`	`position(sub IN s)` / `strpos(s, sub)`	✅	Both syntaxes work
`replace(s, from, to)`	`replace(s, from, to)`	✅	Native DataFusion
`reverse(s)`	`reverse(s)`	✅	Native DataFusion
`rpad(s, size, pad)`	`rpad(s, size, pad)`	✅	Native DataFusion
`rtrim(s)`	`rtrim(s)`	✅	Native DataFusion
`soundex(s)`	`soundex(s)`	✅	Trino compat UDF
`split(s, delim)`	`split(s, delim)`	✅	Trino-aliased on `string_to_array(s, delim)`; returns `ARRAY(VARCHAR)`
`split_part(s, delim, idx)`	`split_part(s, delim, idx)`	✅	Native DataFusion
`strpos(s, sub)`	`strpos(s, sub)`	✅	Trino compat UDF
`substr(s, start, len)`	`substr(s, start, len)`	✅	Native DataFusion
`translate(s, from, to)`	`translate(s, from, to)`	✅	Native DataFusion
`trim(s)`	`trim(s)`	✅	Native DataFusion
`upper(s)`	`upper(s)`	✅	Native DataFusion
`word_stem(s)`	`word_stem(s)`	✅	Trino compat UDF (English default)
`word_stem(s, lang)`	`word_stem(s, lang)`	✅	Single UDF accepts both `word_stem(s)` (English default) and `word_stem(s, lang)`; `word_stem_lang(s, lang)` kept as a registered alias for backward compat. 17 languages

Scalar Functions: Math

Trino Function	SQE Equivalent	Status	Notes
`abs(x)`	`abs(x)`	✅
`acos(x)` / `asin(x)` / `atan(x)`	Same	✅
`atan2(y, x)`	`atan2(y, x)`	✅
`cbrt(x)`	`cbrt(x)`	✅
`ceil(x)` / `ceiling(x)`	`ceil(x)`	✅
`cos(x)` / `sin(x)` / `tan(x)`	`cos(x)` / `sin(x)` / `tan(x)`	✅
`cosh(x)` / `sinh(x)` / `tanh(x)`	Same	✅	Native DataFusion (already built-in)
`degrees(x)`	`degrees(x)`	✅
`e()`	`e()`	✅	Trino compat Nullary UDF returning `std::f64::consts::E`
`exp(x)`	`exp(x)`	✅
`floor(x)`	`floor(x)`	✅
`from_base(s, radix)`	`from_base(s, radix)`	✅	Trino compat UDF
`infinity()`	`infinity()`	✅	Trino compat UDF
`ln(x)`	`ln(x)`	✅
`log(b, x)`	`log(b, x)`	✅
`log2(x)`	`log2(x)`	✅
`log10(x)`	`log10(x)`	✅
`mod(n, m)`	`mod(n, m)`	✅	Trino compat UDF; coerces numeric args to Float64. Errors on `mod(_, 0)` per IEEE 754
`nan()`	`nan()`	✅	Trino compat UDF
`pi()`	`pi()`	✅
`pow(x, p)` / `power(x, p)`	`power(x, p)`	✅
`radians(x)`	`radians(x)`	✅
`rand()` / `random()`	`random()`	✅
`round(x)` / `round(x, d)`	`round(x, d)`	✅
`sign(x)`	`sign(x)`	✅	Trino compat UDF; matches Trino spec including `sign(0) = 0` (Rust’s `f64::signum(0.0)` returns 1.0, so the UDF overrides the zero case)
`sqrt(x)`	`sqrt(x)`	✅
`to_base(n, radix)`	`to_base(n, radix)`	✅	Trino compat UDF
`truncate(x[, n])`	`truncate(x[, n])`	✅	Trino compat UDF; truncates toward zero with optional decimal-precision argument
`width_bucket(x, bound1, bound2, n)`	Same	✅	Native DataFusion (built-in in DF 52)

Scalar Functions: Date/Time

Trino Function	SQE Equivalent	Status	Notes
`current_date`	`current_date`	✅	SQL standard
`current_time`	`current_time`	✅	Native DataFusion (already built-in)
`current_timestamp`	`current_timestamp` / `now()`	✅
`current_timezone()`	`current_timezone()`	✅	Trino compat UDF (returns “UTC”)
`now()`	`now()`	✅	Trino compat UDF
`localtime`	`localtime()`	✅	Trino compat UDF
`localtimestamp`	`localtimestamp()`	✅	Trino compat UDF
`date(s)`	`trino_date(s)`	✅	Trino compat UDF
`from_iso8601_date(s)`	`from_iso8601_date(s)`	✅	Trino compat UDF
`from_iso8601_timestamp(s)`	`from_iso8601_timestamp(s)`	✅	Trino compat UDF
`from_unixtime(n)`	`from_unixtime(n)`	✅	Trino compat UDF
`to_unixtime(ts)`	`to_unixtime(ts)`	✅	Trino compat UDF
`to_iso8601(ts)`	`to_iso8601(ts)`	✅	Trino compat UDF
`date_add(unit, n, ts)`	`date_add(unit, n, ts)`	✅	Trino compat UDF in Trino’s argument order. The previous “different argument order” caveat was a stale doc claim; the implementation in the sqe-trino-functions crate has always taken `(unit, amount, date_or_ts)`, matching Trino’s spec
`date_diff(unit, ts1, ts2)`	`date_diff(unit, ts1, ts2)`	✅	Trino compat UDF
`date_trunc(unit, ts)`	`date_trunc(unit, ts)`	✅	Native DataFusion
`date_format(ts, fmt)`	`date_format(ts, fmt)`	✅	Trino compat UDF (MySQL format codes)
`date_parse(s, fmt)`	`date_parse(s, fmt)`	✅	Trino compat UDF (MySQL format codes)
`format_datetime(ts, fmt)`	`format_datetime(ts, fmt)`	✅	Trino compat UDF (Joda→chrono translation)
`parse_datetime(s, fmt)`	`parse_datetime(s, fmt)`	✅	Trino compat UDF (Joda→chrono translation)
`year(d)`	`year(d)`	✅	Trino compat UDF
`quarter(d)`	`quarter(d)`	✅	Trino compat UDF
`month(d)`	`month(d)`	✅	Trino compat UDF
`week(d)`	`week(d)`	✅	Trino compat UDF
`day(d)` / `day_of_month(d)`	`day(d)`	✅	Trino compat UDF
`day_of_week(d)` / `dow(d)`	`day_of_week(d)`	✅	Trino compat UDF
`day_of_year(d)` / `doy(d)`	`day_of_year(d)`	✅	Trino compat UDF
`hour(ts)`	`hour(ts)`	✅	Trino compat UDF
`minute(ts)`	`minute(ts)`	✅	Trino compat UDF
`second(ts)`	`second(ts)`	✅	Trino compat UDF
`millisecond(ts)`	`millisecond(ts)`	✅	Trino compat UDF
`timezone_hour(ts)`	`timezone_hour(ts)`	✅	Trino compat UDF (returns 0, UTC-only)
`timezone_minute(ts)`	`timezone_minute(ts)`	✅	Trino compat UDF (returns 0, UTC-only)
`with_timezone(ts, tz)`	`with_timezone(ts, tz)`	✅	Trino compat UDF (chrono-tz)
`at_timezone(ts, tz)`	`at_timezone(ts, tz)`	✅	Trino compat UDF (chrono-tz)
`INTERVAL 'n' UNIT`	`INTERVAL 'n' UNIT`	✅	SQL standard
`human_readable_seconds(n)`	`human_readable_seconds(n)`	✅	Trino compat UDF
`last_day_of_month(d)`	`last_day_of_month(d)`	✅	Trino compat UDF

Scalar Functions: JSON

Trino Function	SQE Equivalent	Status	Notes
`json_object(k1, v1, k2, v2, ...)`	`json_object(k1, v1, ...)`	✅	Trino compat UDF
`json_format(json)`	`json_format(json)`	✅	Trino compat UDF
`json_parse(s)`	`json_parse(s)`	✅	Trino compat UDF
`json_extract(json, path)`	`json_extract(json, path)`	✅	Trino compat UDF (dot-path, not full JSONPath)
`json_extract_scalar(json, path)`	`json_extract_scalar(json, path)`	✅	Trino compat UDF
`json_size(json, path)`	`json_size(json, path)`	✅	Trino compat UDF
`json_array_contains(json, val)`	`json_array_contains(json, val)`	✅	Trino compat UDF
`json_array_get(json, idx)`	`json_array_get(json, idx)`	✅	Trino compat UDF (supports negative index)
`json_array_length(json)`	`json_array_length(json)`	✅	Trino compat UDF
`is_json_scalar(json)`	`is_json_scalar(json)`	✅	Trino compat UDF
`CAST(v AS JSON)`	`CAST(v AS JSON)`	✅	sqe-sql AST rewriter intercepts `CAST(... AS JSON)` and rewrites to `to_json(...)` before DataFusion’s planner sees it (DataFusion does not recognize `JSON` as a target type for CAST). Skipped when the SQL does not contain `as json`
`CAST(json AS type)`	`CAST(json_col AS type)`	✅	JSON aliases to `Utf8`; CAST rides DataFusion’s built-in coercion. For typed extraction from JSONPath, use `json_get_int(j, '$')`, `json_get_str(j, '$')`, etc.

Note: Core JSON extraction is now supported via datafusion-functions-json (registered at startup) plus Trino-aliased UDFs (json_extract, json_extract_scalar, json_array_length, json_parse). Full JSONPath syntax and JSON-typed columns remain unsupported — most Iceberg workloads use structured columns rather than JSON blobs.

Scalar Functions: URL

Trino Function	SQE Equivalent	Status	Notes
`url_extract_host(url)`	`url_extract_host(url)`	✅	Trino compat UDF
`url_extract_path(url)`	`url_extract_path(url)`	✅	Trino compat UDF
`url_extract_port(url)`	`url_extract_port(url)`	✅	Trino compat UDF
`url_extract_protocol(url)`	`url_extract_protocol(url)`	✅	Trino compat UDF
`url_extract_query(url)`	`url_extract_query(url)`	✅	Trino compat UDF
`url_extract_parameter(url, name)`	`url_extract_parameter(url, name)`	✅	Trino compat UDF
`url_encode(s)`	`url_encode(s)`	✅	Trino compat UDF
`url_decode(s)`	`url_decode(s)`	✅	Trino compat UDF

Scalar Functions: Regex

Trino Function	SQE Equivalent	Status	Notes
`regexp_count(s, pattern)`	`regexp_count(s, pattern)`	✅	Native DataFusion
`regexp_extract(s, pattern)`	`regexp_extract(s, pattern)`	✅	Trino compat UDF
`regexp_extract_all(s, pattern)`	`regexp_extract_all(s, pattern)`	✅	Returns `ARRAY(VARCHAR)` (was previously a JSON-array string for legacy ARRAY-less callers; re-wired now that DataFusion’s ARRAY plumbing is solid). Errors on invalid regex per Trino spec
`regexp_like(s, pattern)`	`regexp_like(s, pattern)`	✅	Native DataFusion
`regexp_replace(s, pattern, repl)`	`regexp_replace(s, pattern, repl)`	✅
`regexp_split(s, pattern)`	`regexp_split(s, pattern)`	✅	Returns `ARRAY(VARCHAR)`; same re-wiring as `regexp_extract_all`

Scalar Functions: Conditional

Trino Function	SQE Equivalent	Status	Notes
`CASE WHEN ... THEN ... END`	Same	✅	SQL standard
`COALESCE(v1, v2, ...)`	Same	✅
`NULLIF(v1, v2)`	Same	✅
`GREATEST(v1, v2, ...)`	Same	✅	Native DataFusion
`LEAST(v1, v2, ...)`	Same	✅	Native DataFusion
`IF(cond, true, false)`	`trino_if(cond, true, false)`	✅	Trino compat UDF
`TRY(expr)`	`try(expr)`	⚠️	Passthrough UDF; does not catch runtime errors (DataFusion limitation), but query won’t fail with “unknown function”
`TRY_CAST(v AS type)`	`TRY_CAST(v AS type)`	✅	Native DataFusion

Scalar Functions: Conversion / Type Cast

Trino Function	SQE Equivalent	Status	Notes
`CAST(v AS type)`	Same	✅
`TRY_CAST(v AS type)`	Same	✅
`typeof(v)`	`typeof(v)`	✅	Trino compat UDF
`format(fmt, ...)`	`format(fmt, ...)`	✅	Trino compat UDF (%s, %d, %f, zero-pad, precision)
`from_utf8(binary)`	`from_utf8(binary)`	✅	Trino compat UDF
`to_utf8(string)`	`to_utf8(string)`	✅	Trino compat UDF
`from_base64(s)`	`from_base64(s)`	✅	Trino compat UDF
`to_base64(binary)`	`to_base64(binary)`	✅	Trino compat UDF
`from_hex(s)`	`from_hex(s)`	✅	Trino compat UDF
`to_hex(binary)`	`to_hex(binary)`	✅	Trino compat UDF (named to_hex_binary to avoid conflict with DataFusion’s integer to_hex)

Aggregate Functions

Trino Function	SQE Equivalent	Status	Notes
`count(*)` / `count(x)`	Same	✅
`count(DISTINCT x)`	Same	✅
`sum(x)`	Same	✅
`avg(x)`	Same	✅
`min(x)` / `max(x)`	Same	✅
`bool_and(x)` / `bool_or(x)`	`bool_and(x)` / `bool_or(x)`	✅
`every(x)`	`every(x)`	✅	Real aggregate alias on `bool_and_udaf` (replaced an earlier scalar stub that returned the input unchanged and was wrong in any GROUP BY)
`array_agg(x)`	`array_agg(x)`	✅
`array_agg(x ORDER BY y)`	Same	✅	DataFusion supports ordered agg
`string_agg(x, sep)`	`string_agg(x, sep)`	✅
`listagg(x, sep)`	`listagg(x, sep)`	✅	DataFusion’s `string_agg` UDAF re-registered with `listagg` alias
`approx_distinct(x)`	`approx_distinct(x)`	✅
`approx_percentile(x, p)`	`approx_percentile(x, p)`	✅	DataFusion’s `approx_percentile_cont` UDAF re-registered with `approx_percentile` alias
`stddev(x)` / `stddev_samp(x)`	Same	✅
`stddev_pop(x)`	Same	✅
`variance(x)` / `var_samp(x)`	Same	✅
`var_pop(x)`	Same	✅
`covar_samp(y, x)`	`covar_samp(y, x)`	✅
`covar_pop(y, x)`	`covar_pop(y, x)`	✅
`corr(y, x)`	`corr(y, x)`	✅
`regr_slope(y, x)`	`regr_slope(y, x)`	✅
`bitwise_and_agg(x)`	`bitwise_and_agg(x)`	✅	DataFusion’s `bit_and` UDAF re-registered with `bitwise_and_agg` alias
`bitwise_or_agg(x)`	`bitwise_or_agg(x)`	✅	DataFusion’s `bit_or` UDAF re-registered with `bitwise_or_agg` alias
`bitwise_xor_agg(x)`	`bitwise_xor_agg(x)`	✅	DataFusion’s `bit_xor` UDAF re-registered with `bitwise_xor_agg` alias (DuckDB / Snowflake spelling)
`arbitrary(x)`	`arbitrary(x)`	✅	Trino compat UDF (returns first non-null)
`max_by(x, y)` / `min_by(x, y)`	`max_by(x, y)` / `min_by(x, y)`	✅	Real `AggregateUDFImpl` in the sqe-trino-functions crate. Type-flexible (x any type, y any orderable type). `arg_max(x, y)` / `arg_min(x, y)` registered as aliases (DuckDB / ClickHouse spelling)
`histogram(x)`	`histogram(x)`	✅	Real `AggregateUDFImpl` in the sqe-trino-functions crate. Returns `MAP<typeof(x), BIGINT>` with the count per distinct value. Type-flexible key. Multi-phase aggregation supported via `List<Struct{key, count}>` state. NULLs skipped per Trino spec
`multimap_agg(k, v)`	`multimap_agg(k, v)`	✅	Real `AggregateUDFImpl` in the sqe-trino-functions crate. Returns `MAP<typeof(k), ARRAY<typeof(v)>>`. NULL keys skipped; insertion order preserved within each value list
`map_agg(k, v)`	`map_agg(k, v)`	✅	Real `AggregateUDFImpl` in the sqe-trino-functions crate. Returns `MAP<typeof(k), typeof(v)>`. Last-wins on duplicate keys (matches DuckDB / Snowflake)
`map_union(map)`	`map_union(m)`	✅	Real `AggregateUDFImpl` in the sqe-trino-functions crate. Takes a `MAP<K, V>` column and merges every input map into one. Last-wins on duplicate keys
`checksum(x)`	`checksum(x)`	✅	Trino compat UDF (hash-based)
`approx_most_frequent(n, x, cap)`	—	❌
`merge(digest)`	—	❌	HyperLogLog/TDigest
`GROUPING SETS / CUBE / ROLLUP`	Same	✅	Native DataFusion

Window Functions

Trino Function	SQE Equivalent	Status	Notes
`row_number()`	Same	✅
`rank()`	Same	✅
`dense_rank()`	Same	✅
`ntile(n)`	Same	✅
`percent_rank()`	Same	✅
`cume_dist()`	Same	✅
`lead(x, offset, default)`	Same	✅
`lag(x, offset, default)`	Same	✅
`first_value(x)`	Same	✅
`last_value(x)`	Same	✅
`nth_value(x, n)`	Same	✅
Frame specs: ROWS/RANGE/GROUPS	All three supported	✅	Native DataFusion (GROUPS added in DF 19, 2022)
`QUALIFY` clause	Same	✅	Native DataFusion + sqlparser 0.53
Lambda in window functions	—	❌	No lambda support

DDL / DML Statements

Trino Statement	SQE Support	Status	Notes
`CREATE TABLE (cols) WITH (...)`	`CREATE TABLE (cols) WITH (...)`	✅	Trino’s `WITH (foo = 'bar')` syntax merges into table properties via `merge_user_table_properties` in `write_handler.rs:589-590`, alongside `TBLPROPERTIES (...)`. Both spellings produce identical Iceberg metadata
`CREATE TABLE AS SELECT`	Same	✅
`DROP TABLE`	Same	✅
`ALTER TABLE ... RENAME TO`	Same	✅
`ALTER TABLE ... ADD COLUMN`	Same	✅
`ALTER TABLE ... DROP COLUMN`	Same	✅
`ALTER TABLE ... RENAME COLUMN`	Same	✅
`ALTER TABLE ... SET/DROP NOT NULL`	Same	✅
`ALTER TABLE ... SET PROPERTIES`	`ALTER TABLE ... SET TBLPROPERTIES`	✅	Iceberg TableUpdate::SetProperties
`CREATE VIEW`	Same	✅	Iceberg views
`DROP VIEW`	Same	✅
`CREATE OR REPLACE VIEW`	Same	✅	Drop + recreate (non-atomic)
`CREATE MATERIALIZED VIEW`	—	❌	Not in Iceberg spec; use CTAS + scheduled refresh
`INSERT INTO ... VALUES`	Same	✅
`INSERT INTO ... SELECT`	Same	✅
`DELETE FROM ... WHERE`	Same	✅	CoW rewrite_files
`UPDATE ... SET ... WHERE`	Same	✅	CoW rewrite_files
`MERGE INTO ... USING ...`	Same	✅	CoW full-outer-join rewrite
`TRUNCATE TABLE`	`TRUNCATE TABLE t`	✅	Routes to DELETE FROM (no WHERE)
`COMMENT ON TABLE/COLUMN`	Same	✅	Stored as Iceberg table property (`comment` / `comment.<col>`)
`SHOW CATALOGS`	Same	✅
`SHOW SCHEMAS`	Same	✅
`SHOW TABLES`	Same	✅
`SHOW COLUMNS FROM`	`SHOW COLUMNS FROM`	✅	New `handle_show_columns` handler translates Trino’s `SHOW COLUMNS FROM ns.t` into a query against `information_schema.columns`. Returns `(column_name, data_type, is_nullable)`, the subset dbt and BI clients use for schema inspection
`SHOW CREATE TABLE`	Same	✅	Reconstructs DDL from information_schema
`SHOW STATS FOR`	Same	✅	Returns row_count, data_file_count, total_size from snapshot summary
`EXPLAIN`	Same	✅	DataFusion explain
`EXPLAIN ANALYZE`	`EXPLAIN ANALYZE`	✅	Routed through `parse_and_classify` -> `Statement::Explain { analyze: true }` -> `explain_handler.analyze()` since Phase 2; the previous “different keyword” caveat was a stale doc claim. `EXPLAIN FULL` is an SQE-specific extension on top
`USE catalog.schema`	Same	✅	Parsed and accepted (session-level, sets default catalog/schema)
`PREPARE` / `EXECUTE`	Partial	⚠️	DataFusion has infrastructure, SQL integration incomplete
`CALL procedure(...)`	Same (system.* only)	✅	Iceberg maintenance procedures are wired: `CALL system.expire_snapshots(...)`, `CALL system.remove_orphan_files(...)`, `CALL system.rewrite_data_files(...)`, `CALL system.rewrite_manifests(...)`. User-defined stored procedures return an informative `NotImplemented` (“SQE does not have stored procedures”) rather than a parse error
`GRANT` / `REVOKE`	Planned (Plan C)	🔧	SQE-specific grant system

Type System

Trino Type	SQE/Arrow Type	Status	Notes
`BOOLEAN`	`Boolean`	✅
`TINYINT`	`Int8`	✅
`SMALLINT`	`Int16`	✅
`INTEGER`	`Int32`	✅
`BIGINT`	`Int64`	✅
`REAL`	`Float32`	✅
`DOUBLE`	`Float64`	✅
`DECIMAL(p, s)`	`Decimal128(p, s)`	✅	Up to 38 digits
`VARCHAR` / `VARCHAR(n)`	`Utf8` / `Utf8View`	✅	Length limit not enforced
`CHAR(n)`	`Utf8`	✅	Mapped to Utf8; treated as VARCHAR. No fixed-length space-padding (matches Postgres / Snowflake’s CHAR-as-VARCHAR behaviour). Trino itself recommends VARCHAR for new code
`VARBINARY`	`Binary`	✅
`DATE`	`Date32`	✅
`TIME` / `TIME(p)`	`Time64(Microsecond)`	✅	Iceberg’s `time` primitive is microsecond-only; precisions 0..=6 collapse to `Time64(Microsecond)`. `localtime()` returns Time64. `hour() / minute() / second()` work on TIME columns; `year() / month() / day()` raise a clear plan error per Trino spec
`TIME WITH TIME ZONE`	—	❌	No Arrow equivalent. CREATE TABLE rejects with NotImplemented pointing at `TIMESTAMP WITH TIME ZONE`
`TIMESTAMP`	`Timestamp(Microsecond, None)`	✅
`TIMESTAMP WITH TIME ZONE`	`Timestamp(Microsecond, Some(tz))`	✅
`INTERVAL YEAR TO MONTH`	`Interval(YearMonth)`	✅
`INTERVAL DAY TO SECOND`	`Interval(DayTime)`	✅
`ARRAY(T)`	`List(T)`	✅
`MAP(K, V)`	`Map(K, V)`	✅
`ROW(fields...)`	`Struct(fields...)`	✅
`JSON`	`Utf8`	✅	`CREATE TABLE t(payload JSON)` aliases to `Utf8`. `CAST(json_col AS BIGINT
`UUID`	`Utf8`	✅	`CREATE TABLE t(id UUID)` aliases UUID to Utf8 in `sql_type_to_arrow`. Equality, regex, and `CAST(... AS UUID)` work via the string form. No native UUID logical type (Arrow has none); UUIDv4 generation needs a UDF if required
`IPADDRESS`	`VARCHAR`	⚠️	Stored as VARCHAR, no IP-specific functions (subnet containment, etc.)
`HyperLogLog`	—	❌	Trino-specific sketch type
`TDigest`	—	❌	Trino-specific sketch type
`SetDigest`	—	❌	Trino-specific sketch type

Type coercion: DataFusion handles implicit coercion for numeric types (INT → BIGINT → DOUBLE) and string types. Trino has additional coercion rules for JSON, TIME, and sketch types that are not applicable in SQE.

Iceberg-Specific SQL

Feature	SQE Support	Trino Support	Status	Notes
Partition pruning	✅	✅	✅	DataFusion optimizer pass
Hidden partitioning	✅	✅	✅	Via Iceberg transforms
Schema evolution	✅	✅	✅	ADD/DROP/RENAME COLUMN
Type widening	✅	✅	✅	INT→BIGINT, FLOAT→DOUBLE
Time travel: `FOR VERSION AS OF`	`FOR SYSTEM_TIME AS OF`	✅	✅	Pre-processes AST, resolves snapshot_id via metadata
Time travel: `FOR TIMESTAMP AS OF`	Same mechanism	✅	✅	Timestamp resolved to nearest snapshot
`$snapshots` metadata table	`"ns.t$snapshots"` (Trino) or `table_snapshots('ns', 't')` (TVF)	✅	✅	sqe-sql AST rewriter translates `"ns.t$snapshots"` to `table_snapshots('ns', 't')` before DataFusion sees it. Both spellings work; dbt-trino macros that hard-code `$snapshots` resolve transparently
`$manifests` metadata table	`"ns.t$manifests"` or `table_manifests('ns', 't')`	✅	✅	Same rewriter as `$snapshots`
`$history` metadata table	`"ns.t$history"` or `table_history('ns', 't')`	✅	✅	Same rewriter
`$partitions` metadata table	`"ns.t$partitions"` or `table_partitions('ns', 't')`	✅	✅	Same rewriter
`$files` metadata table	`"ns.t$files"` or `table_files('ns', 't')`	✅	✅	Same rewriter
`$refs` metadata table	`"ns.t$refs"` or `table_refs('ns', 't')`	✅	✅	Same rewriter
Partition evolution	✅	✅	✅	Via ALTER TABLE
Sort order	—	✅	❌
Write distribution mode	—	✅	❌
ORC file format	—	✅	❌	Parquet only
Copy-on-Write (CoW)	✅	✅	✅	DELETE/UPDATE/MERGE
Merge-on-Read (MoR) reads	✅	✅	✅	Position deletes, equality deletes, and V3 deletion vectors all readable (RW fork has full read support)
Merge-on-Read (MoR) writes	✅ via `write.delete.mode='merge-on-read'`	✅	✅	`handle_delete_dispatch` routes by table property: position deletes when no PK declared, equality deletes with PK. Position deletes commit via `FastAppendAction`; equality deletes via `RowDeltaAction`. CoW remains the default

Operational Comparison

Run scripts/operational-comparison.sh to regenerate these numbers.

Metric	SQE	Trino	Notes
Language	Rust	Java 23
Build time (release)	~3–5 min	~10–15 min	`cargo build --release` vs `mvn package -DskipTests`
Build dependencies	~800 crates	~2000+ Maven deps	`Cargo.lock` vs `pom.xml` tree
Coordinator binary	~50 MB	N/A (JVM)	Single static binary vs JVM + JARs
Docker image	~80 MB	~700 MB	Alpine + binary vs JVM + plugins
Cold start	<1s	10–30s	First query latency from container start
Idle memory (RSS)	~20 MB	~300 MB	After startup, no queries
Loaded memory	~200–500 MB	~1–4 GB	During TPC-H SF1 full suite
Config surface	~30 TOML knobs	~200+ properties	`sqe.toml` vs `config.properties` + `jvm.config` + catalog files
Deployment	Single binary + TOML	JVM + plugins + properties
Hot reload	❌	❌	Neither supports hot config reload
Plugins	Compile-time features	Runtime JARs	Connectors are Cargo features vs JAR plugins

Key advantages:

10x smaller footprint — single binary, minimal memory
10x faster cold start — no JVM warmup, no class loading
Simpler deployment — one binary, one TOML file
Fewer moving parts — no plugin system, no JVM tuning

Trino advantages:

Ecosystem — 100+ connectors, mature JDBC drivers
Runtime extensibility — add connectors without recompilation
Community — larger community, more Stack Overflow answers

SQE vs Trino