diff --git a/bindings/wasm/lib.rs b/bindings/wasm/lib.rs
index e8c29a360..646e6504e 100644
--- a/bindings/wasm/lib.rs
+++ b/bindings/wasm/lib.rs
@@ -39,4 +39,13 @@ impl limbo_core::PageIO for PageIO {
     fn get(&self, _page_idx: usize, _c: Rc<limbo_core::Completion>) -> Result<()> {
         todo!();
     }
+
+    fn write(
+        &self,
+        _page_idx: usize,
+        _buffer: Rc<std::cell::RefCell<limbo_core::Buffer>>,
+        _c: Rc<limbo_core::WriteCompletion>,
+    ) -> Result<()> {
+        todo!()
+    }
 }
diff --git a/core/lib.rs b/core/lib.rs
index f9ff186e4..91b2084ac 100644
--- a/core/lib.rs
+++ b/core/lib.rs
@@ -18,18 +18,20 @@ use fallible_iterator::FallibleIterator;
 use log::trace;
 use pager::Pager;
 use schema::Schema;
+use sqlite3_ondisk::DatabaseHeader;
 use sqlite3_parser::{ast::Cmd, lexer::sql::Parser};
-use std::rc::Rc;
+use std::{cell::RefCell, rc::Rc};
 
 #[cfg(feature = "fs")]
 pub use io::PlatformIO;
-pub use io::{Buffer, Completion, File, IO};
+pub use io::{Buffer, Completion, File, WriteCompletion, IO};
 pub use storage::{PageIO, PageSource};
 pub use types::Value;
 
 pub struct Database {
     pager: Rc<Pager>,
     schema: Rc<Schema>,
+    header: Rc<RefCell<DatabaseHeader>>,
 }
 
 impl Database {
@@ -43,11 +45,16 @@ impl Database {
     pub fn open(io: Rc<dyn crate::io::IO>, page_source: PageSource) -> Result<Database> {
         let db_header = Pager::begin_open(&page_source)?;
         io.run_once()?;
-        let pager = Rc::new(Pager::finish_open(db_header, page_source)?);
+        let pager = Rc::new(Pager::finish_open(
+            db_header.clone(),
+            page_source,
+            io.clone(),
+        )?);
         let bootstrap_schema = Rc::new(Schema::new());
         let conn = Connection {
             pager: pager.clone(),
             schema: bootstrap_schema.clone(),
+            header: db_header.clone(),
         };
         let mut schema = Schema::new();
         let rows = conn.query("SELECT * FROM sqlite_schema")?;
@@ -74,13 +81,19 @@ impl Database {
             }
         }
         let schema = Rc::new(schema);
-        Ok(Database { pager, schema })
+        let header = db_header;
+        Ok(Database {
+            pager,
+            schema,
+            header,
+        })
     }
 
     pub fn connect(&self) -> Connection {
         Connection {
             pager: self.pager.clone(),
             schema: self.schema.clone(),
+            header: self.header.clone(),
         }
     }
 }
@@ -88,6 +101,7 @@ impl Database {
 pub struct Connection {
     pager: Rc<Pager>,
     schema: Rc<Schema>,
+    header: Rc<RefCell<DatabaseHeader>>,
 }
 
 impl Connection {
@@ -99,7 +113,12 @@ impl Connection {
         if let Some(cmd) = cmd {
             match cmd {
                 Cmd::Stmt(stmt) => {
-                    let program = Rc::new(translate::translate(&self.schema, stmt)?);
+                    let program = Rc::new(translate::translate(
+                        &self.schema,
+                        stmt,
+                        self.header.clone(),
+                        self.pager.clone(),
+                    )?);
                     Ok(Statement::new(program, self.pager.clone()))
                 }
                 Cmd::Explain(_stmt) => todo!(),
@@ -118,12 +137,22 @@ impl Connection {
         if let Some(cmd) = cmd {
             match cmd {
                 Cmd::Stmt(stmt) => {
-                    let program = Rc::new(translate::translate(&self.schema, stmt)?);
+                    let program = Rc::new(translate::translate(
+                        &self.schema,
+                        stmt,
+                        self.header.clone(),
+                        self.pager.clone(),
+                    )?);
                     let stmt = Statement::new(program, self.pager.clone());
                     Ok(Some(Rows { stmt }))
                 }
                 Cmd::Explain(stmt) => {
-                    let program = translate::translate(&self.schema, stmt)?;
+                    let program = translate::translate(
+                        &self.schema,
+                        stmt,
+                        self.header.clone(),
+                        self.pager.clone(),
+                    )?;
                     program.explain();
                     Ok(None)
                 }
@@ -141,12 +170,22 @@ impl Connection {
         if let Some(cmd) = cmd {
             match cmd {
                 Cmd::Explain(stmt) => {
-                    let program = translate::translate(&self.schema, stmt)?;
+                    let program = translate::translate(
+                        &self.schema,
+                        stmt,
+                        self.header.clone(),
+                        self.pager.clone(),
+                    )?;
                     program.explain();
                 }
                 Cmd::ExplainQueryPlan(_stmt) => todo!(),
                 Cmd::Stmt(stmt) => {
-                    let program = translate::translate(&self.schema, stmt)?;
+                    let program = translate::translate(
+                        &self.schema,
+                        stmt,
+                        self.header.clone(),
+                        self.pager.clone(),
+                    )?;
                     let mut state = vdbe::ProgramState::new(program.max_registers);
                     program.step(&mut state, self.pager.clone())?;
                 }
diff --git a/core/pager.rs b/core/pager.rs
index 3665eba67..c8275bb48 100644
--- a/core/pager.rs
+++ b/core/pager.rs
@@ -5,6 +5,7 @@ use crate::PageSource;
 use log::trace;
 use sieve_cache::SieveCache;
 use std::cell::RefCell;
+use std::hash::Hash;
 use std::rc::Rc;
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::RwLock;
@@ -72,13 +73,36 @@ impl Page {
     }
 }
 
+pub struct PageCache<K: Eq + Hash + Clone, V> {
+    cache: SieveCache<K, V>,
+}
+
+impl<K: Eq + Hash + Clone, V> PageCache<K, V> {
+    pub fn new(cache: SieveCache<K, V>) -> Self {
+        Self { cache }
+    }
+
+    pub fn insert(&mut self, key: K, value: V) {
+        self.cache.insert(key, value);
+    }
+
+    pub fn get(&mut self, key: &K) -> Option<&V> {
+        self.cache.get(key)
+    }
+
+    pub fn resize(&mut self, capacity: usize) {
+        self.cache = SieveCache::new(capacity).unwrap();
+    }
+}
+
 /// The pager interface implements the persistence layer by providing access
 /// to pages of the database file, including caching, concurrency control, and
 /// transaction management.
 pub struct Pager {
-    page_source: PageSource,
-    page_cache: RefCell<SieveCache<usize, Rc<Page>>>,
+    pub page_source: PageSource,
+    page_cache: RefCell<PageCache<usize, Rc<Page>>>,
     buffer_pool: Rc<BufferPool>,
+    pub io: Rc<dyn crate::io::IO>,
 }
 
 impl Pager {
@@ -89,15 +113,17 @@ impl Pager {
     pub fn finish_open(
         db_header: Rc<RefCell<DatabaseHeader>>,
         page_source: PageSource,
+        io: Rc<dyn crate::io::IO>,
     ) -> anyhow::Result<Self> {
         let db_header = db_header.borrow();
         let page_size = db_header.page_size as usize;
         let buffer_pool = Rc::new(BufferPool::new(page_size));
-        let page_cache = RefCell::new(SieveCache::new(10).unwrap());
+        let page_cache = RefCell::new(PageCache::new(SieveCache::new(10).unwrap()));
         Ok(Self {
             page_source,
             buffer_pool,
             page_cache,
+            io,
         })
     }
 
@@ -119,4 +145,12 @@ impl Pager {
         page_cache.insert(page_idx, page.clone());
         Ok(page)
     }
+
+    pub fn write_database_header(&self, header: &DatabaseHeader) {
+        sqlite3_ondisk::begin_write_database_header(header, self).expect("failed to write header");
+    }
+
+    pub fn change_page_cache_size(&self, capacity: usize) {
+        self.page_cache.borrow_mut().resize(capacity);
+    }
 }
diff --git a/core/sqlite3_ondisk.rs b/core/sqlite3_ondisk.rs
index 94516dbfb..5f9223d24 100644
--- a/core/sqlite3_ondisk.rs
+++ b/core/sqlite3_ondisk.rs
@@ -18,14 +18,14 @@
 /// +-----------------+----------------+---------------------+----------------+
 /// |                 |                |                     |                |
 /// |   Page header   |  Cell pointer  |     Unallocated     |  Cell content  |
-/// | (8 or 12 bytes) |     array      |        space        |      area      |      
+/// | (8 or 12 bytes) |     array      |        space        |      area      |
 /// |                 |                |                     |                |
 /// +-----------------+----------------+---------------------+----------------+
 ///
 /// For more information, see: https://www.sqlite.org/fileformat.html
 use crate::buffer_pool::BufferPool;
-use crate::io::{Buffer, Completion};
-use crate::pager::Page;
+use crate::io::{Buffer, Completion, WriteCompletion};
+use crate::pager::{Page, Pager};
 use crate::types::{OwnedRecord, OwnedValue};
 use crate::PageSource;
 use anyhow::{anyhow, Result};
@@ -35,8 +35,13 @@ use std::rc::Rc;
 
 /// The size of the database header in bytes.
 pub const DATABASE_HEADER_SIZE: usize = 100;
+// DEFAULT_CACHE_SIZE negative values mean that we store the amount of pages a XKiB of memory can hold.
+// We can calculate "real" cache size by diving by page size.
+const DEFAULT_CACHE_SIZE: i32 = -2000;
+// Minimun number of pages that cache can hold.
+pub const MIN_PAGE_CACHE_SIZE: usize = 10;
 
-#[derive(Debug, Default)]
+#[derive(Debug, Default, Clone)]
 pub struct DatabaseHeader {
     magic: [u8; 16],
     pub page_size: u16,
@@ -52,7 +57,7 @@ pub struct DatabaseHeader {
     freelist_pages: u32,
     schema_cookie: u32,
     schema_format: u32,
-    default_cache_size: u32,
+    pub default_cache_size: i32,
     vacuum: u32,
     text_encoding: u32,
     user_version: u32,
@@ -79,7 +84,7 @@ pub fn begin_read_database_header(page_source: &PageSource) -> Result<Rc<RefCell
 
 fn finish_read_database_header(buf: &Buffer, header: Rc<RefCell<DatabaseHeader>>) -> Result<()> {
     let buf = buf.as_slice();
-    let mut header = header.borrow_mut();
+    let mut header = std::cell::RefCell::borrow_mut(&header);
     header.magic.copy_from_slice(&buf[0..16]);
     header.page_size = u16::from_be_bytes([buf[16], buf[17]]);
     header.write_version = buf[18];
@@ -94,7 +99,10 @@ fn finish_read_database_header(buf: &Buffer, header: Rc<RefCell<DatabaseHeader>>
     header.freelist_pages = u32::from_be_bytes([buf[36], buf[37], buf[38], buf[39]]);
     header.schema_cookie = u32::from_be_bytes([buf[40], buf[41], buf[42], buf[43]]);
     header.schema_format = u32::from_be_bytes([buf[44], buf[45], buf[46], buf[47]]);
-    header.default_cache_size = u32::from_be_bytes([buf[48], buf[49], buf[50], buf[51]]);
+    header.default_cache_size = i32::from_be_bytes([buf[48], buf[49], buf[50], buf[51]]);
+    if header.default_cache_size == 0 {
+        header.default_cache_size = DEFAULT_CACHE_SIZE;
+    }
     header.vacuum = u32::from_be_bytes([buf[52], buf[53], buf[54], buf[55]]);
     header.text_encoding = u32::from_be_bytes([buf[56], buf[57], buf[58], buf[59]]);
     header.user_version = u32::from_be_bytes([buf[60], buf[61], buf[62], buf[63]]);
@@ -106,6 +114,76 @@ fn finish_read_database_header(buf: &Buffer, header: Rc<RefCell<DatabaseHeader>>
     Ok(())
 }
 
+pub fn begin_write_database_header(header: &DatabaseHeader, pager: &Pager) -> Result<()> {
+    let header = Rc::new(header.clone());
+    let page_source = Rc::new(pager.page_source.clone());
+
+    let drop_fn = Rc::new(|_buf| {});
+    let buffer_to_copy = Rc::new(RefCell::new(Buffer::allocate(512, drop_fn)));
+    let buffer_to_copy_in_cb = buffer_to_copy.clone();
+
+    let header_cb = header.clone();
+    let complete = Box::new(move |buffer: &Buffer| {
+        let header = header_cb.clone();
+        let buffer: Buffer = buffer.clone();
+        let buffer = Rc::new(RefCell::new(buffer));
+        {
+            let mut buf_mut = std::cell::RefCell::borrow_mut(&buffer);
+            let buf = buf_mut.as_mut_slice();
+            buf[0..16].copy_from_slice(&header.magic);
+            buf[16..18].copy_from_slice(&header.page_size.to_be_bytes());
+            buf[18] = header.write_version;
+            buf[19] = header.read_version;
+            buf[20] = header.unused_space;
+            buf[21] = header.max_embed_frac;
+            buf[22] = header.min_embed_frac;
+            buf[23] = header.min_leaf_frac;
+            buf[24..28].copy_from_slice(&header.change_counter.to_be_bytes());
+            buf[28..32].copy_from_slice(&header.database_size.to_be_bytes());
+            buf[32..36].copy_from_slice(&header.freelist_trunk_page.to_be_bytes());
+            buf[36..40].copy_from_slice(&header.freelist_pages.to_be_bytes());
+            buf[40..44].copy_from_slice(&header.schema_cookie.to_be_bytes());
+            buf[44..48].copy_from_slice(&header.schema_format.to_be_bytes());
+            buf[48..52].copy_from_slice(&header.default_cache_size.to_be_bytes());
+
+            buf[52..56].copy_from_slice(&header.vacuum.to_be_bytes());
+            buf[56..60].copy_from_slice(&header.text_encoding.to_be_bytes());
+            buf[60..64].copy_from_slice(&header.user_version.to_be_bytes());
+            buf[64..68].copy_from_slice(&header.incremental_vacuum.to_be_bytes());
+
+            buf[68..72].copy_from_slice(&header.application_id.to_be_bytes());
+            buf[72..92].copy_from_slice(&header.reserved);
+            buf[92..96].copy_from_slice(&header.version_valid_for.to_be_bytes());
+            buf[96..100].copy_from_slice(&header.version_number.to_be_bytes());
+            let mut buffer_to_copy = std::cell::RefCell::borrow_mut(&buffer_to_copy_in_cb);
+            let buffer_to_copy_slice = buffer_to_copy.as_mut_slice();
+
+            buffer_to_copy_slice.copy_from_slice(buf);
+        }
+    });
+
+    let drop_fn = Rc::new(|_buf| {});
+    let buf = Buffer::allocate(512, drop_fn);
+    let c = Rc::new(Completion::new(buf.clone(), complete));
+    page_source.get(1, c.clone())?;
+    // run get header block
+    pager.io.run_once()?;
+
+    let buffer_in_cb = buffer_to_copy.clone();
+    let write_complete = Box::new(move |bytes_written: usize| {
+        let buf = buffer_in_cb.clone();
+        let buf_len = std::cell::RefCell::borrow(&buf).len();
+        if bytes_written < buf_len {
+            log::error!("wrote({bytes_written}) less than expected({buf_len})");
+        }
+        // finish_read_database_header(buf, header).unwrap();
+    });
+    let c = Rc::new(WriteCompletion::new(write_complete));
+    page_source.write(0, buffer_to_copy.clone(), c).unwrap();
+
+    Ok(())
+}
+
 #[derive(Debug)]
 pub struct BTreePageHeader {
     page_type: PageType,
diff --git a/core/storage.rs b/core/storage.rs
index 95a1b3257..a9d2fc995 100644
--- a/core/storage.rs
+++ b/core/storage.rs
@@ -1,13 +1,24 @@
-use crate::io::Completion;
 #[cfg(feature = "fs")]
 use crate::io::File;
+use crate::{
+    io::{Completion, WriteCompletion},
+    Buffer,
+};
 use anyhow::Result;
-use std::rc::Rc;
+use std::{cell::RefCell, rc::Rc};
 
 pub struct PageSource {
     io: Rc<dyn PageIO>,
 }
 
+impl Clone for PageSource {
+    fn clone(&self) -> Self {
+        Self {
+            io: self.io.clone(),
+        }
+    }
+}
+
 impl PageSource {
     pub fn from_io(io: Rc<dyn PageIO>) -> Self {
         Self { io }
@@ -23,10 +34,25 @@ impl PageSource {
     pub fn get(&self, page_idx: usize, c: Rc<Completion>) -> Result<()> {
         self.io.get(page_idx, c)
     }
+
+    pub fn write(
+        &self,
+        page_idx: usize,
+        buffer: Rc<RefCell<Buffer>>,
+        c: Rc<WriteCompletion>,
+    ) -> Result<()> {
+        self.io.write(page_idx, buffer, c)
+    }
 }
 
 pub trait PageIO {
     fn get(&self, page_idx: usize, c: Rc<Completion>) -> Result<()>;
+    fn write(
+        &self,
+        page_idx: usize,
+        buffer: Rc<RefCell<Buffer>>,
+        c: Rc<WriteCompletion>,
+    ) -> Result<()>;
 }
 
 #[cfg(feature = "fs")]
@@ -46,6 +72,20 @@ impl PageIO for FileStorage {
         self.file.pread(pos, c)?;
         Ok(())
     }
+
+    fn write(
+        &self,
+        page_idx: usize,
+        buffer: Rc<RefCell<Buffer>>,
+        c: Rc<WriteCompletion>,
+    ) -> Result<()> {
+        let buffer_size = buffer.borrow().len();
+        assert!(buffer_size >= 512);
+        assert!(buffer_size <= 65536);
+        assert!((buffer_size & (buffer_size - 1)) == 0);
+        self.file.pwrite(page_idx, buffer, c)?;
+        Ok(())
+    }
 }
 
 #[cfg(feature = "fs")]
diff --git a/core/translate.rs b/core/translate.rs
index 482a51616..182a9297f 100644
--- a/core/translate.rs
+++ b/core/translate.rs
@@ -1,16 +1,65 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+
+use crate::pager::Pager;
 use crate::schema::Schema;
+use crate::sqlite3_ondisk::{DatabaseHeader, MIN_PAGE_CACHE_SIZE};
 use crate::vdbe::{Insn, Program, ProgramBuilder};
 use anyhow::Result;
-use sqlite3_parser::ast::{Expr, Literal, OneSelect, Select, Stmt};
+use sqlite3_parser::ast::{
+    Expr, Literal, OneSelect, PragmaBody, QualifiedName, Select, Stmt, UnaryOperator,
+};
 
 /// Translate SQL statement into bytecode program.
-pub fn translate(schema: &Schema, stmt: Stmt) -> Result<Program> {
+pub fn translate(
+    schema: &Schema,
+    stmt: Stmt,
+    database_header: Rc<RefCell<DatabaseHeader>>,
+    pager: Rc<Pager>,
+) -> Result<Program> {
     match stmt {
         Stmt::Select(select) => translate_select(schema, select),
+        Stmt::Pragma(name, body) => translate_pragma(&name, body, database_header, pager),
         _ => todo!(),
     }
 }
 
+pub fn update_pragma(
+    name: &String,
+    value: i64,
+    header: Rc<RefCell<DatabaseHeader>>,
+    pager: Rc<Pager>,
+) {
+    match name.as_str() {
+        "cache_size" => {
+            let mut cache_size_unformatted = value;
+            let mut cache_size = if cache_size_unformatted < 0 {
+                let kb = cache_size_unformatted.abs() * 1024;
+                kb / 512 // assume 512 page size for now
+            } else {
+                value
+            } as usize;
+            if cache_size < MIN_PAGE_CACHE_SIZE {
+                // update both in memory and stored disk value
+                cache_size = MIN_PAGE_CACHE_SIZE;
+                cache_size_unformatted = MIN_PAGE_CACHE_SIZE as i64;
+            }
+
+            // update in-memory header
+            header.borrow_mut().default_cache_size = cache_size_unformatted
+                .try_into()
+                .expect(&format!("invalid value, too big for a i32 {}", value));
+
+            // update in disk
+            let header_copy = header.borrow().clone();
+            pager.write_database_header(&header_copy);
+
+            // update cache size
+            pager.change_page_cache_size(cache_size);
+        }
+        _ => todo!(),
+    }
+}
 fn translate_select(schema: &Schema, select: Select) -> Result<Program> {
     let mut program = ProgramBuilder::new();
     let init_offset = program.emit_placeholder();
@@ -218,3 +267,60 @@ fn translate_expr(
         Expr::Variable(_) => todo!(),
     }
 }
+
+fn translate_pragma(
+    name: &QualifiedName,
+    body: Option<PragmaBody>,
+    database_header: Rc<RefCell<DatabaseHeader>>,
+    pager: Rc<Pager>,
+) -> Result<Program> {
+    let mut program = ProgramBuilder::new();
+    let init_offset = program.emit_placeholder();
+    let start_offset = program.offset();
+    match body {
+        None => {
+            let pragma_result = program.alloc_register();
+
+            program.emit_insn(Insn::Integer {
+                value: database_header.borrow().default_cache_size.into(),
+                dest: pragma_result,
+            });
+
+            let pragma_result_end = program.next_free_register();
+            program.emit_insn(Insn::ResultRow {
+                register_start: pragma_result,
+                register_end: pragma_result_end,
+            });
+        }
+        Some(PragmaBody::Equals(value)) => {
+            let value_to_update = match value {
+                Expr::Literal(Literal::Numeric(numeric_value)) => {
+                    numeric_value.parse::<i64>().unwrap()
+                }
+                Expr::Unary(UnaryOperator::Negative, expr) => match *expr {
+                    Expr::Literal(Literal::Numeric(numeric_value)) => {
+                        -numeric_value.parse::<i64>().unwrap()
+                    }
+                    _ => 0,
+                },
+                _ => 0,
+            };
+            update_pragma(&name.name.0, value_to_update, database_header, pager);
+        }
+        Some(PragmaBody::Call(_)) => {
+            todo!()
+        }
+    };
+    program.emit_insn(Insn::Halt);
+    program.fixup_insn(
+        init_offset,
+        Insn::Init {
+            target_pc: program.offset(),
+        },
+    );
+    program.emit_insn(Insn::Transaction);
+    program.emit_insn(Insn::Goto {
+        target_pc: start_offset,
+    });
+    Ok(program.build())
+}
diff --git a/core/vdbe.rs b/core/vdbe.rs
index 0df9d9753..6b39a5ed1 100644
--- a/core/vdbe.rs
+++ b/core/vdbe.rs
@@ -3,6 +3,7 @@ use crate::pager::Pager;
 use crate::types::{Cursor, CursorResult, OwnedValue, Record};
 
 use anyhow::Result;
+use core::fmt;
 use std::cell::RefCell;
 use std::collections::BTreeMap;
 use std::rc::Rc;
@@ -363,15 +364,37 @@ fn print_insn(addr: usize, insn: &Insn) {
     println!("{}", s);
 }
 
+enum IntValue {
+    Int(i64),
+    Usize(usize),
+}
+
+impl fmt::Display for IntValue {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            IntValue::Int(i) => f.pad(i.to_string().as_str()),
+            IntValue::Usize(i) => f.pad(i.to_string().as_str()),
+        }
+    }
+}
+
 fn insn_to_str(addr: usize, insn: &Insn) -> String {
-    let (opcode, p1, p2, p3, p4, p5, comment) = match insn {
+    let (opcode, p1, p2, p3, p4, p5, comment): (
+        &str,
+        IntValue,
+        IntValue,
+        IntValue,
+        &str,
+        IntValue,
+        String,
+    ) = match insn {
         Insn::Init { target_pc } => (
             "Init",
-            0,
-            *target_pc,
-            0,
+            IntValue::Usize(0),
+            IntValue::Usize(*target_pc),
+            IntValue::Usize(0),
             "",
-            0,
+            IntValue::Usize(0),
             format!("Start at {}", target_pc),
         ),
         Insn::OpenReadAsync {
@@ -379,25 +402,41 @@ fn insn_to_str(addr: usize, insn: &Insn) -> String {
             root_page,
         } => (
             "OpenReadAsync",
-            *cursor_id,
-            *root_page,
-            0,
+            IntValue::Usize(*cursor_id),
+            IntValue::Usize(*root_page),
+            IntValue::Usize(0),
             "",
-            0,
+            IntValue::Usize(0),
             format!("root={}", root_page),
         ),
-        Insn::OpenReadAwait => ("OpenReadAwait", 0, 0, 0, "", 0, "".to_string()),
-        Insn::RewindAsync { cursor_id } => ("RewindAsync", *cursor_id, 0, 0, "", 0, "".to_string()),
+        Insn::OpenReadAwait => (
+            "OpenReadAwait",
+            IntValue::Usize(0),
+            IntValue::Usize(0),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
+        Insn::RewindAsync { cursor_id } => (
+            "RewindAsync",
+            IntValue::Usize(*cursor_id),
+            IntValue::Usize(0),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
         Insn::RewindAwait {
             cursor_id,
             pc_if_empty,
         } => (
             "RewindAwait",
-            *cursor_id,
-            *pc_if_empty,
-            0,
+            IntValue::Usize(*cursor_id),
+            IntValue::Usize(*pc_if_empty),
+            IntValue::Usize(0),
             "",
-            0,
+            IntValue::Usize(0),
             "".to_string(),
         ),
         Insn::Column {
@@ -406,11 +445,11 @@ fn insn_to_str(addr: usize, insn: &Insn) -> String {
             dest,
         } => (
             "Column",
-            *cursor_id,
-            *column,
-            *dest,
+            IntValue::Usize(*cursor_id),
+            IntValue::Usize(*column),
+            IntValue::Usize(*dest),
             "",
-            0,
+            IntValue::Usize(0),
             format!("r[{}]= cursor {} column {}", dest, cursor_id, column),
         ),
         Insn::ResultRow {
@@ -418,45 +457,97 @@ fn insn_to_str(addr: usize, insn: &Insn) -> String {
             register_end,
         } => (
             "ResultRow",
-            *register_start,
-            *register_end,
-            0,
+            IntValue::Usize(*register_start),
+            IntValue::Usize(*register_end),
+            IntValue::Usize(0),
             "",
-            0,
+            IntValue::Usize(0),
             format!("output=r[{}..{}]", register_start, register_end),
         ),
-        Insn::NextAsync { cursor_id } => ("NextAsync", *cursor_id, 0, 0, "", 0, "".to_string()),
+        Insn::NextAsync { cursor_id } => (
+            "NextAsync",
+            IntValue::Usize(*cursor_id),
+            IntValue::Usize(0),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
         Insn::NextAwait {
             cursor_id,
             pc_if_next,
         } => (
             "NextAwait",
-            *cursor_id,
-            *pc_if_next,
-            0,
+            IntValue::Usize(*cursor_id),
+            IntValue::Usize(*pc_if_next),
+            IntValue::Usize(0),
             "",
-            0,
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
+        Insn::Halt => (
+            "Halt",
+            IntValue::Usize(0),
+            IntValue::Usize(0),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
+        Insn::Transaction => (
+            "Transaction",
+            IntValue::Usize(0),
+            IntValue::Usize(0),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
+        Insn::Goto { target_pc } => (
+            "Goto",
+            IntValue::Usize(0),
+            IntValue::Usize(*target_pc),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
+        Insn::Integer { value, dest } => (
+            "Integer",
+            IntValue::Usize(*dest),
+            IntValue::Int(*value),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
             "".to_string(),
         ),
-        Insn::Halt => ("Halt", 0, 0, 0, "", 0, "".to_string()),
-        Insn::Transaction => ("Transaction", 0, 0, 0, "", 0, "".to_string()),
-        Insn::Goto { target_pc } => ("Goto", 0, *target_pc, 0, "", 0, "".to_string()),
-        Insn::Integer { value, dest } => {
-            ("Integer", *dest, *value as usize, 0, "", 0, "".to_string())
-        }
         Insn::String8 { value, dest } => (
             "String8",
-            *dest,
-            0,
-            0,
+            IntValue::Usize(*dest),
+            IntValue::Usize(0),
+            IntValue::Usize(0),
             value.as_str(),
-            0,
+            IntValue::Usize(0),
             format!("r[{}]= '{}'", dest, value),
         ),
-        Insn::RowId { cursor_id, dest } => ("RowId", *cursor_id, *dest, 0, "", 0, "".to_string()),
-        Insn::DecrJumpZero { reg, target_pc } => {
-            ("DecrJumpZero", *reg, *target_pc, 0, "", 0, "".to_string())
-        }
+        Insn::RowId { cursor_id, dest } => (
+            "RowId",
+            IntValue::Usize(*cursor_id),
+            IntValue::Usize(*dest),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
+        Insn::DecrJumpZero { reg, target_pc } => (
+            "DecrJumpZero",
+            IntValue::Usize(*reg),
+            IntValue::Usize(*target_pc),
+            IntValue::Usize(0),
+            "",
+            IntValue::Usize(0),
+            "".to_string(),
+        ),
     };
     format!(
         "{:<4}  {:<13}  {:<4}  {:<4}  {:<4}  {:<13}  {:<2}  {}",